The Reloading Press is an at-least-weekly feature here on Gaming Ballistic for 2016. Each week it looks at some interesting real-world cartridges and presents them with hopefully-useful information in GURPS Format.

.22 LR/5.6x15mmR

The .22 LR was designed just shy of 1890, as a modification – or at least inspired by – the Flobert BB cap and the .22 S&W of 1857. It was originally a black powder cartridge, and the various loadings and velocities reflect the range from “indoor target use against not-much-other-than-paper” to “wartime use in WW2 in suppressed pistols” to “varmint killin’,” with a lot of plinking and competitive shooting in between.

The fairly low cost and extremely versatile design make it one of the most popular, if not the most popular, chamberings for firearms in the world. The low recoil, high accuracy (remember: Olympics), and general ease of loading and shooting, plus the traditionally low cost (recent shortages in the USA are somewhat of an aberration) make it a great chambering to teach marksmanship, firearms handling, and discipline.

The basic inputs will be driven from the highest energy projectile that’s a standard load: the copper-plated 31gr (2 gram) round-nose bullet fired at 1750fps. This projectile is still less than half the energy of a 9mm.
Ballistic’s Calculator Inputs

Basic inputs for the calculator are as follows, selecting 458mm (18″) for the (test) barrel length.

INPUT
.22LR
Chamber Pressure 25000 psi
Barrel bore 5.6 mm
Case Length 15 mm
Chamber Bore 5.6 mm
Barrel length 458 mm
Bullet Mass 31 grains
Aspect Ratio 1.9 L/Bore
Burn length 10.04 mm
Projectile Caliber 5.6 mm
Total Accelerated Mass 31 grains
Expansion Ratio 1.6 expansion

Output Stats

The rated cartridge is on the higher-energy end of things, but shows behavior that more or less defines the round.

Notes
  • The velocity is at the muzzle. The velocity with the 18″ test barrel is tuned to match the 1750fps for a 31gr bullet. There are many other loads available, but my practice is to take the highest energy commonly listed.
  • The .22LR, even in hollow-point, do not expand enough to give any GURPS benefit for wounding – that is, even a JHP will not expand enough to eke out pi instead of pi-. So the damage is pi- from the muzzle to the limits of range.
The notable features of the .22LR includes the quickness with which the velocity plateaus: once you get to an 11″ barrel, you will not increase velocity enough to get to 2d+1 unless you get to a 31″ barrel . . . and even carefully tuned .22LR projectiles with slow-burning powder, in the real world, start to lose velocity out of a 26″ barrel as pressure starts to decrease faster than barrel friction is increasing. For most standard loads, the longest practical barrel is on the order of 18-19″ (460-480mm).

The literature lists the .22LR as a “150-yard” cartridge. This is due to the transition down to subsonic velocity, and the accuracy degrades measurably from that point. This coincides nicely with the 1/2D range calculated.

This is, was, and always will be an anemic cartridge that is going to depend greatly on shot placement. To the vitals out of a 5″ through 19″ barrel, you can get 6-36 points of damage – plenty enough to kill an unarmored average man. To the skull, you will get 0-40 points, with a fairly low but not unrealistic chance of the bullet deflecting off the skull. 

Anywhere else, you will need to hit a lot. 

Alternate Loads


If you go out and buy a brick of .22LR without some care for getting the maximum energy out of the load, you will likely bring home 40gr projectiles at about 1200fps out of an 18″ barrel. These carry a bit better (1/2D of around 210yds), but do even less damage (1d+2) out of an 18″ barrel. The transition to 2d-1 is at nearly 24″, making it (in reality) top out at the 1d+2 pi- level. It will drop below 1d+2 to 1d+1 at 40-100mm barrel length. So standard .22LR will be 1d+1 out of pocket pistols, and 1d+2 out of rifles.

Very subsonic .22LR exists firing a 60gr bullet at 950fps. This is a 340-yd 1/2D and is about right for 1d+2 pi- at the muzzle of a 18″ rifle. Unlike it’s lightweight cousins, it can expand in JHP format to do pi damage, but base damage drops to 1d+1. Out of a pistol with a 4″ barrel, it will do 1d (0.5) pi as a JHP round, or 1d pi- as a ball round (the copper-washed bullets do not usually qualify as having a metal ‘jacket’ to speak of).

There are snake-shot rounds firing shotshell as well. This is 30grains of #12 shot, each of which weighs about 0.2 grains (!). Wound channel modifier is on the order of 0.1, basically four size modifiers lower than even a pi- round. Penetration is notionally 2d, but this is an artifact of the 1.5mm diameter of the projectile in the model. Best to treat this as RoF 6, 2d (0.2) pi-, clustering groups of pellets together. 

Platforms


There are a vast, vast number of .22LR guns out there. Some classics:

Ruger 10/22 semi-auto rifle. This 18.5″ barrel semi-auto rifle comes in a lot of styles, and is a good plinker for novice and experienced shooters alike. Comes with a 10-round rotary magazine that fits flush with the rifle, or a 25-round box.

In a pistol, the small form factor and low recoil of the round makes it fairly attractive for attaching accessories . . . such as a suppressor. This would include the Walther P22 pictured to the right. This shows a 3.4″ barreled pistol with a suppressor that is as long as the overall firearm itself. 

An unusual .22 LR pistol is the Calico M110, whose helical-fed magazine holds 100 rounds of .22LR. It’s a very unusual looking pistol (and also available in 50- and 100-round capacity as the M950/960 in 9mm) and if you need 100 rounds of .22LR on tap in an otherwise bulky gun, this is what you want. The rifle-length barreled versions are apparently fairly attractive conversions to full-auto, due to low recoil -effectively a precursor to the 4.6x30mm and 5.8x28mm PDW-style weapons with roughly the same projectile weight but using a bottlenecked round to get a lot more energy out of the package.

The concept of the suppressed .22LR has been around for a long time, and saw service as the Ruger High-Standard HDM in WW2. This modified Ruger Mark 1 (and later, Mark II and Mark III) is purpose-built for the role.

Without providing a picture, it should also be noted that conversion kits – often a magazine well insert, a new chamber/barrel, or (in the case of the already-.22″ caliber AR15) simply a new bolt assembly – for many firearms are available, allowing you to swap your usual caliber for the usually less expensive .22LR. This can be especially attractive given that  1,000 rounds of .22LR can be had for $150, while 1,000 rounds of 62-gr M855 style ammo will run about $350-400. 

The Reloading Press is an at-least-weekly feature here on Gaming Ballistic for 2016. Each week it looks at some interesting real-world cartridges and presents them with hopefully-useful information in GURPS Format.

5.45x39mm 7N6

The 5.45x39mm cartridge was a follow-on design to the original 7.62x39mm M43 and M67 that embraced the lightweight bullet concept.

The bullet construction features a lot of steel, making this relatively high-aspect-ratio projectile lose velocity (and thus damage) faster than both the 7.62x39mm and the 5.56x45mm projectile (the 7N6 seems to be about 20-25% less dense than the M193 lead 5.56mm bullet).

The cartridge itself propels a 53gr projectile with a steel core and copper-washed steel jacket. Martin Fackler, my favorite ballistician, performed tests that showed that the bullet, on striking flesh, will tumble roughly twice in 45cm of gelatin, but due to the steel construction, is unlikely to tumble and fragment. This would tend to indicate that it might have a pi- damage rating, but it’s high length sideways pushes that up to pi. 

Ballistic’s Calculator Inputs

Basic inputs for the calculator are as follows, selecting 415mm for the (test) barrel length. The Pact-standard M43 steel-core FMJ round was selected as the basic package.

INPUT
7.62x39mm
Chamber Pressure 45000 psi
Barrel bore 7.62 mm
Case Length 39 mm
Chamber Bore 10 mm
Barrel length 415 mm
Bullet Mass 123 grains
Aspect Ratio 3.5 L/Bore
Burn length 25.8 mm
Projectile Caliber 7.62 mm
Total Accelerated Mass 123 grains
Expansion Ratio 2 expansion
Projectile Load 1
Output Stats

This is the classic “adversary” round for modern action and any sort of late cold war game. This replaced the 7.62x39mm in many uses in Russia and the Soviet Union.

The recoil impulse of this round is very, very light – perhaps 2/3 to half of even it’s cousin the 5.56x45mm, and the energetics show it: only 1328J from a standard 415mm barrel, compared to about 1760J for the NATO counterpart.

The bullet is supposed to penetrate armor better than the 5.56x45mm, but the stats don’t show it. This would be based on the steel construction of the bullet rather than the energetics of the system, which give it a 1-2 point disadvantage in raw penetration relative to the 5.56mm.

Notes
  • The velocity is at the muzzle. The velocity with a 415 test barrel is tuned to match real-world data from the 7N6at 1328J muzzle energy, the standard military load issued in bulk. 
  • The bullet will only do pi- damage at barrel lengths shorter than 137mm. From there, the velocity chosen for the drop to pi- is 600m/s, which is somewhat arbitrary.
The typical barrel lengths for this rifle are in the 8-10″ range for very short rifles (230mm barrel would be 4d pi to 120yds), a carbine at 314mm (4d+1 pi; 180yds pi- range), and a “full length” barrel of 415mm (4d+2 pi; 225yd pi- range). 

Alternate Loads

There are a few militarily important variants.

The 7N6M has a hardened steel core for enhanced penetration – the core is hardened to Rc 60, in fact, which is respectable for even sword steel (higher Rc numbers in the 61-64 range are common for the edges of hardened sword steel in the japanese katana, for example). It will penetrate 6Zh85T body armor at 80m.

The 7N10 increases the weight to 55.6gr, maintains the velocity at 880m/s, and improves penetration such that it will defeat the same body armor out to 200m.

Two dedicated AP bullets, the 7N22 AP and 7N24 “super” AP were produced. The 7N22 is 57gr at 890m/s (5d pi raw damage, probably something like a 1.25 armor divisor) while the 64gr 7N24 has a true tungsten carbide penetrator and the same energy, but will hit for 5d (2) pi- if it doesn’t tumble, and 5d (2) pi if it does.

There’s also a subsonic version, 7U1, which is 80gr at 303m/s for about 2d pi-. Better hit something important.

Platforms

AK-74


The original 5.45x39mm weapon is mostly indistinguishable from the AK-47, and due to the year of introduction, it’s called the AK-74. Plastic magazines, an indentation in the wooden stock, and slight differences in the gas tube are about it.

AK-105

A more recent version of this chambering is the AK-105, with a 314mm barrel instead of the usual 415mm one for the AK-74. The smaller barrel reduces the velocity of the round.

The Vepr was to be a bullpup version of the AK-74 for Ukraine, but wasn’t ever really seriously deployed.

Vepr

One interesting variant is the AN-94, made from 1994-2006. It’s claim to fame was the super-fast cyclic rate of a two-round controlled burst. It also, to quote from wikipedia, features in the design that the barrel, gas tube, receiver, and bolt carrier all exist as a single component group moving back and forth along an axis parallel to the bore, suspended within what the Russian manufacturers call an Effect-Envelope—the external composite fibre/polymer stock. This configuration separates the events inside the rifle from what the person operating the weapon actually experiences (i.e. low recoil).

The SSG 82 was a bolt-action rifle with a 600mm barrel chambered for the 5.45x39mm cartridge.

AN-94

The Reloading Press is an at-least-weekly feature here on Gaming Ballistic for 2016. Each week it looks at some interesting real-world cartridges and presents them with hopefully-useful information in GURPS Format.

7.62x39mm M43


The 7.62x39mm cartridge cleared all of the major hurdles to design and mass production in 1947, and remains one of the most popular chamberings for combat rifles in the world, almost certainly due to its proliferation by the Soviet Union. It’s archetypical platform, the AK-47 assault rifle, is one of the only weapons to appear on a national flag. It’s that iconic.

The original “assault rifle” concept was an intermediate. Of intermediate power between a pistol and a battle rifle, intermediate chambering, intermediate velocity, intermediate lots of things. 

The cartridge itself propels a 123gr (just shy of 8gr) bullet that is actually 7.92mm in diameter, with a steel core and copper-washed steel jacket. Martin Fackler, my favorite ballistician, has good things to say about the design relative to prior projectiles, but notes it’s quite stable in flesh, and the sturdy construction of the bullet makes it unlikely to either tumble quickly or fragment badly, limiting its wounding potential. That’s not to say it hasn’t killed plenty of folks worldwide.

Ballistic’s Calculator Inputs

Basic inputs for the calculator are as follows, selecting 415mm for the (test) barrel length. The Pact-standard M43 steel-core FMJ round was selected as the basic package.

INPUT
7.62x39mm
Chamber Pressure 45000 psi
Barrel bore 7.62 mm
Case Length 39 mm
Chamber Bore 10 mm
Barrel length 415 mm
Bullet Mass 123 grains
Aspect Ratio 3.5 L/Bore
Burn length 25.8 mm
Projectile Caliber 7.62 mm
Total Accelerated Mass 123 grains
Expansion Ratio 2 expansion
Projectile Load 1
Output Stats

This is the classic “adversary” round for modern action and any sort of cold war game. It found use in both the Soviet Union and China, and is still rather popular in Africa and the Middle East. And the USA. And . . . you get the point.

In any case: the original M43 bullet is optimized out of a 415mm (about 16.3″) barrel, and the longest barrel I could find was a 26″ bolt-action gun. This is not a long-barrel cartridge, by any stretch of the imagination. If you want that and want a Soviet/Russian round, use the 7.62x54mmR. 

But that being said, sometimes you make do with what you have. And the RPD light machinegun does shoot from a 520mm barrel, so there you go.

Notes
  • The velocity is at the muzzle. The velocity with a 16.3″ test barrel is tuned to match real-world data from the M43 at 2178J muzzle energy, the standard military load issued in bulk. Later rounds were issued with the slightly lower energy M67 projectile.
  • There is no pi to pi- range listed for this cartridge, because the projectile will always do at least pi damage. As even the armor piercing channel is 0.8, there’s no point in a pi- rating. The round’s tendency to not yaw and fragment speaks against any sort of pi+ rating at any range.
The typical barrel lengths for this rifle are in the 8-10″ range for very short rifles, the standard 415mm barrel, and the 520mm barrel of the light machinegun. Given the number of rifles and variants, anything from a low of about 7.5″ to the 26″ barrel mentioned earlier probably exist.

Alternate Loads

There don’t seem to be the huge variety of loads that are featured on (say) the 7.62x51mm NATO rounds. That said, there are two important variants that exist.

After 1989, a heat-treatment process was introduced, along with a higher carbon tool steel, that improved the penetration of the standard bullet by 2-3x (!). This would usually qualify as an AP variant. However, since the AK47 isn’t notable for being a high-threat projectile for modern body armor, that might argue that pre-1989 bullets earn themselves a (0.5) armor divisor, and modern construction would simply be (1). So the old variant might do 5d+2 (0.5) pi, while the modern is 5d+2 pi.

There are also soft-point and hollow point versions, which would come in at 4d+1 pi+ using my usual conversion.

Platforms


There’s really just the one. 

OK, that’s a ridiculous lie. But if you stopped and started with the AK-47, you wouldn’t go far wrong. These can be stamped out by the kajillions, or purchased nearly custom to get the nearly oxymoronic high-end AK.

Other variants include the AKM (modernized AK47) and shortened versions such as the AKMS for paratrooper use. The AKM is, I’m told, the most common mass-produced variant of this weapon, with the a cheaper stamped, rather than milled, receiver.

The SKS is a more traditional-looking clip-fed rifle.

Some pretty interesting variants exist, including this bullpup version.

Thursday is GURPSDay, and a conversation on the Forums about modeling on-the-range use of Guns got me thinking about something. I suspect that it will cause a few issues when the rubber meets the road, but I also kind of like the general concepts.

Right now, there are three flavors of fighting skills. The Combat version, which might be things like Karate, Judo, and Guns. This is the stuff you use in an actual fight.

But then there are the Combat Art and Combat Sport skills for exhibition (Art) or competition (Sport). These are mostly geared to hand-to-hand combat skills, so they’re not entirely great fits. Guns Art might be trick shooting, while Guns Sport might be IPSC or IDPA (defensive and practical pistol competitions), Paintball or Airsoft, or other formalized shooting events. Guns (Combat) is basically infantry training with simunitions or live ammo, shoot-house, formation fighting, plus a lot of range time.

The thing about range time is that it’s range time. Even when it’s timed or otherwise restricted, the Drill Instructor is unlikely to toss a grenade into your firing lane, or your next-door neighbor to either try and punch you in the face or shoot you in the head.

That’s the kind of thing that is simulated by Combat skills in GURPS.


Target Difficulties


One big help was provided in GURPS Tactical Shooting by listing the kinds of modifiers that can accrue when not shooting in a real combat environment. These include

  • Up to +3 for risk factors to self, others, and stake in the outcome
  • Up to +4 for the environment. Low end is a designated but unimproved outdoor range, high end is a perfectly-lit indoor facility with lanes, seating, etc.
  • Up to +3 for knowing precisely the range and speed (usually constant and zero, respectively) of the target
This is a pretty good list, though some of these things are hard to adjudicate in play. Back before Tactical Shooting came out, I’d posited a pretty similar list. I wouldn’t endorse all of my choices from back then, but I would consider looking at those pesky ‘environment’ variables and seeing if they can be made more explicit. Because +4 is being able to shoot basically 5x farther or in a 5x tighter group relative to without that bonus. It’s the difference between a crappy snubnose and a carbine with aim. It’s huge.
But for the sake of completeness and precision, let’s see if we can break down some of the more clumpy bits. The risk factors are already in +1 increments, so moving on, starting with the Range/Speed factor.
Hitting a target is more or less knowing hold-over – where do you put the sights relative to where you want the bullet to go at a given distance. That’s given a +3 in the rules for rangefinder, and it’s a flat-out yes/no bonus. Hrm. Let’s actually leave that as-is. 
I’m tempted to broaden it a bit, and allow giving that “rangefinder” bonus for ranges where it just doesn’t matter what the range is – that is, very close range. 
What’s very close? Well, that depends on the “zero” for the gun. Ugh – that’s problematical in play, because who really wants to figure that out? But if we take a look at some ballistic trajectories, you’ll find that with iron sights zeroed at 25yds, a 9mm will rise up about a quarter inch, and then drop by that much at about 30yds. Beyond that, it’s all downhill. The 9mm has a 1/2D range of about 150yds in GURPS. 1/4 of that distance is between 35-40yds.
If we look at a .223 sighted in at 25 yds from a flat-top receiver with iron sights, with the sights about 3/4 over the bore (OK, lots of assumptions on a rifle), the bullet rises from -0.75″ at the muzzle, peaks at about +0.75″ high, and returns to -0.75″ low at between 150 and 200 yds. The 1/2D for this rifle is 600yds, and 1/4 of that is 150yds. 
So to first approximation, at distances of less than about 1/4 the 1/2D range (yeesh), you basically don’t need to know the range. If you aim directly at the target, you will hit within one inch of it. Rangefinding and bullet-drop compensation only matters past this distance.
And only while actually using the Aim maneuver or using sighted shooting. Snap shooting doesn’t benefit from this knowledge at all.
That means that aimed fire on most shooting ranges – less than about 25yds for a pistol, less than 150-250yds for a rifle (depends on caliber, config, etc), you just point at the target, carefully, and you don’t have to know anything about ballistics. 
So, we’ve got an adjustable +3 for risk factors (+1 each for three factors), a binary +3 for either knowing the range and ballistic information for your weapon/ammo combination or being at lower than 1/4 of the 1/2D range and taking an Aim maneuver . . . and up to +4 from environment. 

In short, another way to phrase this: The bonus for All-Out Attack (Determined) might be considered as +4 up to 1/4 of 1/2D range, but +1 beyond that. If you are within the 1/4 of 1/2D (I hate typing that!), then you’ve already eaten the rangefinder bonus; if you’re past that range, you may still claim it if you actually do know the range.

This is where I’m going to deviate from the very big bonus for being on an outdoor range vs a perfectly lit indoor range with air conditioning, etc. That’s because a lot of this stuff is factored in to other penalties: good lighting is assumed. Wind isn’t explicitly, but is only usually figured in when using optional rules like Time of Flight from Tactical Shooting, but again, lack of wind (or at least no severe winds) is probably assumed.
So I’m going to break that usual +4 allocated to environment a bit differently:
  • +1 for a high-contrast “shoot me here” target, including bulls-eyes and concentric rings
  • +1 for an isolated and comfortable shooting position. At a table, your own lane, etc.
  • +1 for target moving predictably or not at all.
  • +1 for no target movement at all (so that stacks with the above); you only get this if the target is stationary, unmoving, and there’s zero chance of any moving air disturbing the shot
This lumps in “moving target” with “wind,” which is sorta true if you wave your fingers at it a bit.
The net result of this is that plinking at garbage at 20yds on an outdoor range with a pistol will definitely get you:
  • +3 for no risks
  • +3 because you don’t even need to know the range
  • +1 for no movement of the target at all but being outdoors.
You might be able to claim isolated and comfortable if you have pre-built or pre-prepared shooting positions, but shooting at junk is probably not worth the “screams I’m a target at you” bonus. So definitely +7, maybe +8, not +9 or +10.
Known ranges, brightly contrasting targets, prepared positions, unmoving, but outside. +9.
Going through a one person shoot-house with live ammo? I’d give +2 for no risk to self or others, but dock the final +1 because of the time pressure, which gives a stake in the outcome. A proper shoot-house will be close range, so you’d probably claim the +3 for known or irrelevant range . . . but by and large you’re not going to be taking Aim maneuvers in these. If you did, you’ll nail it. Indoor shoot-houses with unmoving targets will qualify for the +2, but manikins in clothing aren’t high-visibility targets and there are often “decoy” no-shoot targets too. 
Net benefit +4 for most situations, +7 if you get to aim, though you may run out of time. Probably TDM of +4. If the situation is made purposefully stressful – people shouting at you, setting off firecrackers, or whatever, that might drop down to +2 (for unmoving targets) because you’ve tricked yourself into believing that there’s a risk to both yourself (though not a risk of harm, but a risk of failure) and to others (you can’t shoot the good-guy dummies!).

Note that this doesn’t account for time taken for target discrimination and Identify-Friend-or-Foe activity. If you don’t have to make that choice and pick from targets, you can probably go very quickly and very accurately. Proper realistic training tries to get down as low as possible here.

Wow, that’s a lot of bonuses available, even for somewhat stressful activity! Surely that will produce hit rates that are far, far too high!
Yes. But . . . 
Combat is a Very Hard skill

The second half of this is to recognize that combat skills are very hard. Oh, sure . . . shooting is fairly easy. It’s mechanical, it doesn’t involve gross body movements for the act itself, and pointing a weapon and pulling the trigger are extensions of each other.

But what would happen if we just made  Guns into a DX/VH skill and assumed that the “sport” or “art” versions simply benefit from the Task Difficulty Modifiers above?
Firstly, the relative change between 1 point in a DX/E skill and 1 point in a DX/H skill is -3, since 1 point gives you the skill at DX+0 for DX/E and DX-3 for DX/VH.
Hey, that’s already the difference between Sport and Combat skills. So no real change there, other than you never have to buy the skills separately. If you want to judge yourself on following the rules of a particular shooting sport? Buy Games skill for that competition style’s rules.
All of a sudden, that first point in Guns for Joe Average gives you Guns-7 rather than Guns-10 . . . but thanks to the TDMs for shooting carefully on an indoor range, the base skill there will likely be Guns-17 for a start, +2 for Acc, +1 for more aim, and another +2 for All-Out Attack with two hands on the pistol. So one shot ever few seconds has total “positive” modifiers starting at Guns-22, and at -4 for 10 yards and -1 for “torso to head” on the paper will be “on paper” basically every time with a net skill of Guns-17.
Head shots at 10 yds is -4 for range, -5 for head for 22-9, or Guns-11, or about 2 in 3 in the head area. Skull would be 1 in 3.
What if you’re putting – as I have with an XDM in .40S&W – 15 rounds into less than 2″ at 5yds? -2 for range, -8 for a 2″ hole. Net skill needs to be on the order of 16 to do this reliably. Bonuses for that gun was Acc3, +2 more for careful aim. AoA(Determined, Braced) for another +2. +10 for TDM. 
Skill +7 (Aim and Brace) +10 (TDM) – 10 (Range and size) = 16 implies I have a minimum of Guns-9, which is DX-1 or 4 points in Guns at the DX/VH level.

Edited to Add: A comment over on Google+ by the esteemed (well, by me at least) +Luke Campbell notes that the +3 that you get for “inside a certain fraction of the 1/2D range” is already included in the Acc stats of line-of-sight beam weapons. This is precisely true, and it’s true at all ranges, not just at “point blank.” A useful addition.

Parting Shot

In practice, it means world-class Guns skills are going to be harder to achieve. Getting to Guns-18, “exceptional” hostage rescue operators and snipers, can be pretty trivial when you’re sporting DX 12 to DX 14 for an athletic combatant and only need DX+4 or DX+6 on an Easy skill to get there. DX is its own reward, but even DX 10 and Guns-18 is 28 points.
Granted, the switch-over to DX/VH only adds 12 points to that calculus, so Guns-18 and DX 10 would be 40 points, and DX 13 (SEAL template) and Guns-18 is a 60+28 = 88 point investment. It does mean that you will be spending 8 points to get to DX level in a combat skill instead of 1 point, which makes it cooler to be a high-skill guns guy.
It means that with lower skills, you need more bonuses. Aim, brace, and any TDMs you can eke out. Less frantic gunfights, with more time for move and cover. You’ll need to do it, because otherwise you’ll just miss.
It also means that “no TDM for combat” can be relaxed a bit. A sniper might . . . might . . . claim the +1 for “no risk to self,” but I doubt it. At short range, though, you will often get the benefit of the “point blank” bonus (also the range-finding bonus) of +3 when you Aim above and beyond the firearm’s accuracy. 
That range might be a tetch high, though. Having the +3 be available with almost any Aim maneuver with a pistol means that the Aim gives most modern guns +5 or +6 at close range . . . and the net result of that is simply to return skills to where they were before the switch to DX/VH.
But it also means that you don’t have to invoke crazy penalties to get hit rates in tune with actual observed gunfights. A point or two in Guns (Pistol) with a DX 10 or DX 11 police officer (or a point in Guns (Rifle) and a DX 10 recruit) is Guns-7 to maybe Guns -9. At five or seven yards with unaimed fire you’re down to a net skill of Guns-5 or Guns-6, and not much more than that with sighted shooting for AoA(Determined, Braced), hitting maybe 25% of the time even when the lighting and footing is good!
You start to use your sights and take an Aim, and your natural Acc combines with point-blank for about +5, with AoA(Determined/Braced) for +7 total, on top of Guns-5 or Guns-7, and your net skill for the torso is Guns-12 to Guns-14. Vitals? Guns-9 to Guns-11.
Again, for street-level shooting, that’s quite good.

Now, this sort of thing is only going to please the crowd that really wants their low-level PCs to be kinda bad – the kinda bad that you see in real-world even report stats. And moving Guns to DX/VH when freakin’ Judo and Karate are DX/H? Maybe that’s just crazy-talk.
The thing that offsets the two is that you can make an All-Out Telegraphic Attack for +8 to skill when you’ve got melee. When push comes to shove, you can add huge values to your skill in a pinch. Both guns and fists suffer the same level of target penalties – shooting and punching the face are both -5.  And more importantly, range penalties are dreadfully high, and occur on every shot greater than 3yds.
So why make guns harder then they already are? It’s a valid question. I’m not sure I have an answer.
What I’ve tried to do here is two-fold
  1. Make explicit the Task Difficulty Modifiers for guns, which is really breaking down the environmental bonuses to the same level the already-explicit rangefinding and risk bonuses are.
  2. Get rid of the need for Guns Sport (or even Guns Art) as a thing by making the provision of sport/art use simply part of the TDM assignment.
That second piece gets rid of the usual argument (well, it’s an argument I’ve seen before) that many or even most shooters are using Guns Sport because they only train on the range. And so when they get into combat, they’re really operating at a -3 to their skill all the time anyway because the conditions are so unlike range shooting.
I think that may all well be true, but the usual operating GURPS mantra is that the skill represents adventuring usage. The hardest part about shooting in combat is the combat itself. The risk to life and limb. 
I’m sure that I and lots of other people that can put 15 shots of 9mm into a 1.5-2″ hole at 10yds would see huge degradations in accuracy in an actual combat situation. Badly. I think the modifiers above do a credible job of unifying the presence/absence of stress and the assuredness with which you can blaze away at a target range.
I don’t know, however, if my players would stand for it. I suspect not. Eh . . . a lot of what I do on the blog is just a design exercise anyway. This one probably achieves its goals, but I’m not sure it fits well within the larger GURPS framework.

I should also add that this kind of thing will make hash out of cinematic shoot-em-up games, as it’s designed to detract from the “Everything is Awesome!” nature of easy-high guns skill (see what I did there, Bad Cop?). As a design exercise, then, we’d need to see what would be required – and that might just be “tons more points” to make cinematic shooters properly affordable. 

On the other hand, with the relative ease of instant death (or at least instant incapacitation) available slinging around 3d to 7d pi damage with a large ammo capacity available, making heroes work for hits a bit more (and thus distinguishing even more from mooks, who really won’t be able to hit squat) might not be awful.

It also means that using suppressive fire even for low RoF weapons may well be the default usage . . . and that’s not wrong, is it?

The Reloading Press is an at-least-weekly feature here on Gaming Ballistic for 2016. Each week it looks at some interesting real-world cartridges and presents them with hopefully-useful information in GURPS Format.

6.5x39mm (6.5 Grendel)

The 6.5 Grendel was designed with the goal to give the AR-15 platform “legs” out to 200-800 yard, and even farther if possible. It started life as a variant of the 6.5 PPC, both of which were derived from the .220  Russian cartridge. As you can see from the cut-away, it features a fairly short and squat chamber case – which is excellent for combustion – and a long bullet.

Almost ridiculously long, actually. Though it’s not shown, the 120gr solid copper bullet has an overall length (OAL) of 35.56mm (1.4″) and an actual bullet diameter of 6.71mm (0.264″), for an aspect ratio of about 5.3, compared to about 3.9 for a 5.56x45mm. This is done purposefully, as high sectional density is a great way to get long range out of the projectile.

And get long range it does. With heavier bullets (130gr rather than the highest-energy version modeled as standard here), the penetration at 1,000 yards is modeled as 5% higher than even the 7.62x51mm NATO standard 147gr projectile (and a scant 1.25% less than the 168gr match bullet). So mission accomplished from that perspective.

But what do you give up? There’s always a trade-off, right?

Ballistic’s Calculator Inputs

Basic inputs for the calculator are as follows, selecting 406mm for the (test) barrel length.

INPUT
  6.5 Grendel  
Chamber Pressure 50000 psi
Barrel bore 6.71 mm
Case Length 38.7 mm
Chamber Bore 10.87 mm
Barrel length 609.6 mm
Bullet Mass 130 grains
Aspect Ratio 5.3 L/Bore
Burn length 21.62 mm
Projectile Caliber 6.71 mm
Total Accelerated Mass 130 grains
Expansion Ratio 2 expansion
Projectile Load 1
Output Stats

This cartridge/projectile is one that has sufficient caveats from a real-world perspective that the chart isn’t going to tell you everything.

That being said, the standard rifles with this cartridge are delivered can toss out 123gr projectiles out of an AR-15 platform that are still supersonic at 1,200 yards. 

Out of the 24″ test barrel (610mm), the bullet develops 823m/s from the muzzle, and has a higher 1/2D range than the 150gr 7.62x51mm NATO round by about 55yds. 

The projectile is just small enough that you have to worry about a pi- to pi transition from a front-on perspective, but the darn thing is so long that if it yaws in flesh it’ll do some ugly stuff. It’ll drop below 600m/s at 185yds with a 14.5″ barrel (such as the M4 carbine) and stay there to 300yds with the 24″ sniper barrel.

Barrel lengths sold by the vendor include 16″, 18″, 20″, and 24″. So all of the available platforms will range from 6d-1 pi to 6d+1 pi, but can reach out as far as much heavier rifles and rounds.

So, here’s the chart:

Notes
  • The velocity is at the muzzle. The velocity with a 24″ test barrel is tuned to match real-world data at 2700fps with a 120gr solid copper projecile, the highest energy load listed on the Wiki page. I do this because GURPS damage is based on kinetic energy, so no GURPS PC worth their salt will choose anything less than the highest energy if pure penetration/lethality is at issue. If you’re doing suppressed subsonic shooting, that changes.
There are heavier and lighter bullets available; I’ve read that heavier bullets have issues due to stabilization, and if you start shooting a lightweight bullet here, I suspect you give up the substantial sectional density advantages of a long, heavy bullet.

This seems to be a very, very niche cartridge. It does what it does very well: it extends the effective range of an AR15 platform out to 800-1,000 yards. This gives you advantages in ammunition weight and magazine capacity (the 6.5 Grendel mags hold 26 rounds each), and potentially a very light rifle.

However, the restrictions on the performance sweet spot of the round (120-130 grains, apparently) and that it seems to do what it does best out of fairly long barrels (20-24″) means that this is going to be a firearm that mostly designated marksmen and snipers will love . . . but if you’re only sending one or two rounds at a time downrange, you might as well carry something more substantial. And if you’re looking for a round that does as well out of a carbine as it does out of a sniper/marksman’s platform, my understanding is that this isn’t your go-to.

Properly loaded and matched to a barrel/powder combination, match bullets easily hit 0.75 to 0.85 MoA at range – again, very handy for an AR-15.

    Platforms

    You need a purpose-built upper receiver (or at least a barrel, chamber, and bolt change) to shoot this cartridge. The proprietary cartridge and upper seem to only be sold by Alexander Arms, the inventor of the round. The rifle can run you from $1,150 to $3,200 depending on parts and accessories, but if you already have a lower receiver, you can get into 6.5 Grendel for $650-$2,000. The higher priced models are presumably with tighter tolerances and better parts overall, such as free-float barrels.

      The Reloading Press is an at-least-weekly feature here on Gaming Ballistic for 2016. Each week it looks at some interesting real-world cartridges and presents them with hopefully-useful information in GURPS Format.

      7.62x51mm NATO

      The 7.62x51mm cartridge occupies an interesting place in the US military history. After the tremendous success of the .30-06 semi-automatic weapon in WW2 with the M1 Garand rifle, the army was looking for a cartridge more suitable than the 63mm-long .30-06 for semi-automatic fire as well as potentially automatic fire. The Brits were interested in the .276 Pederson and .280 British, both of which were designed with a mind towards full-auto controllability. The USA, in a doctrinal choice which must seem baffling given where we are today, insisted in a .30 caliber cartridge to preserve the effectiveness of single shots out to 2,000 yards (!). 

      The 7.62x51mm was made possible by improved manufacturing processes, with the cartridge nearly a half-inch shorter than the .30-06, but loaded to a slightly lower velocity.

      Either the British or the USA rounds would have been acceptable to Canada at the time – they took the “Eh, whatever the US does, eh?” approach, and so NATO went with the .308 . . . which proved to be just as uncontrollable from shoulder-fired infantry weapons as might have been imagined. That didn’t prevent it from being highly effective in the machinegun role, with the M60 and later M240. The temporary wound channel of the .308 bullet can be the size of a volleyball in the right conditions, and the permanent cavity is very large as well (and devastatingly so if the round happens to be prone to fragmentation). Users of the projectile will swear by its ability to put a foe down; they’re not wrong.

      The cartridge continues to see service in various forms, including as a sniper platform, as well as in theaters such as Afghanistan, where accurate long-ranged fire really is a mission requirement. There are a large number of variants of the projectile, and this article will try and cover the most military important. 


      Ballistic’s Calculator Inputs

      Basic inputs for the calculator are as follows, selecting 610mm for the (test) barrel length. The NATO-standard M80 ball round was selected as the basic package.

      INPUT
      150gr NATO 7.62x51mm
      Chamber Pressure 50000 psi
      Barrel bore 7.62 mm
      Case Length 51 mm
      Chamber Bore 11.53 mm
      Barrel length 609.6 mm
      Bullet Mass 147 grains
      Aspect Ratio 3.65 L/Bore
      Burn length 23.6 mm
      Projectile Caliber 7.62 mm
      Total Accelerated Mass 147 grains
      Expansion Ratio 2.2 expansion
      Projectile Load 1
      Output Stats

      This is the archetypical 7d rifle for GURPS, and the output for the 24″ test barrel is so near to exactly 7d calculated penetration that it’s almost amusing. Of course, for handiness and weight, barrels go quite shorter than this in the real world, with a 16″ barrel being common enough that designing a purpose-built cartridge that is .30 caliber, achieves the same test muzzle velocity, and does so out of a 16″ barrel makes a lot of sense (note that the 6.8x43mm SPC seems to have done exactly that, though with a .27″ instead of a .30″ projectile). 

      In any case:

      Notes
      • The velocity is at the muzzle. The velocity with a 24″ test barrel is tuned to match real-world data at 2750fps, the standard military load issued in bulk. 
      • There is no pi to pi- range listed for this cartridge, because the projectile will always do at least pi damage. There’s a good case to be made here that this round might do pi+ under some circumstances, and even pi++ in others (see Alternate Loads, below).
      • This round is one of the grounding points (along with the 9mm and .50BMG) in my ballistics model, so this one really should (and does) match the published penetration values.
      At any useful barrel length this will equal the performance of the 5.56x45mm cartridge that replaced it in terms of terminal performance. The ammo will always be heavier, of course, and each magazine is going to carry 20 rounds for military issue rather than the 30 of the .223/5.56. Unless you’re in the full-auto business with a dedicated weapon, though, the high recoil (and GURPS Rcl) of the round will keep you in the three semi-auto shots business.

      Take note that the test barrel is very, very long for a modern combat arm (but not for cold-war era rifles). Anything that will be issued in a role that’s not point shooting (snipers, designated marksmen) is likely going to have a barrel in the 16-20″ range these days, which means you’ll be dealing 6d+1 to 7d-1 instead of the usual 7d with the standard M80 FMJ.

      That, of course, is far from the only option, and PCs should be choosy if they’re really desirous of the 7.62 (or if they’re being forced to use it because it’s standard issue). 

      Alternate Loads


      There are a bewildering number of alternative loads for this cartridge. I sorted through the Wiki page and picked out some important ones from the military pile, will make a note of civilian expanding rounds, and also throw down with a SLAP (saboted light armor piercing) projectile which is just plain nasty.

      What follows is effectively a heavily trimmed selection from the 7.62x51mm Wiki page.

      M198 (United States): 7.62×51mm NATO duplex round with two 84-grain (5.4 g) bullets. The first hits at 2750 fps for 5d, and it’s a hair’s breadth under the 0.75 wound channel mod to get it a full pi. The back projectile tends to be slower at 2200fps (4d pi).  I’d give both pi at less than about 50yds, and pi- at more than that.  1/2D is 275yds. This was more or less a failed experiment.


      M276 (United States): 7.62×51mm NATO so-called “Dim Tracer” for use with night vision devices. Stats basically the same as M80 (150gr bullet).

      M852 (United States): 168-grain (10.9 g) 7.62×51mm NATO Hollow-Point Boat-Tail cartridge, specifically designed for use in National Match competitions. It replaced the M118SB as the standard Match round. The bullet was very accurate at around 300 meters (competition match ranges) but suffered at longer ranges. 1/2D increases to 650yds, wound channel gets a tiny bump to 0.85. Velocity is a bit lower (2,550fps), so out of a 24″ barrel it will do 24.2 points of damage – call it 7d-1, though an oddly specified 6d+3 pi would be good too. Muzzle energy 3,290 J. Consider this mass-production match ammo.
      M993 (United States): 126.6 grains (8.2 g) 7.62×51mm NATO armor-piercing round, black cartridge tip. This projectile uses a tungsten core surrounded by an aluminum cup and copper jacket. The 126.6gr total projectile weight slows down a bit faster (1/2D 450yds), but does 7d (2) pi out of the muzzle, delivering about 3,400J at that point. My understanding is these are very expensive.

      MK 316 MOD 0 (United States): A 175-grain (11.3 g) round specifically designed for long-range sniping. With a 1/2D of roughly 700yds and 7d+1 from the muzzle, this ammo supposedly (from the right platform) will maintain 1 MoA out to 1,000 yds. Definitely match ammo – supposedly about the best quality you can get to minimize dispersion given a variety of in-the-field conditions.

      T762TNB1 MK319 MOD 0 (United States): 7.62×51mm NATO Enhance Behind barrier performance Enhance Function & casualty and muzzle flash requirements in short barrel carbines, 130 grains (8.4 g). The bullet pushes about 2925fps from a 16″ barrel (call id 5d+7; the barrier blind property is what gives it the odd penetration value) using a combination of slightly elevated pressure and longer burn. The cost is designed to be close to the M80, or at least as close as possible, but you probably can’t take that to the bank. 1/2D 45oyds from 16″ barrel, and 3,350J muzzle energy. The base of the bullet is solid copper and designed to be what pushes through the barrier . . . not sure if this will drop the wound from pi to pi-; it’s quite possible.

      DM111, Weichkern, (Germany): 147-grain (9.5 g) 7.62×51mm NATO ball cartridge, cupronickel-coated steel jacket. German equivalent to U.S. M80 round. In service with the German military. Known for severe fragmentation in human tissue due to its thin jacket, particularly around the cannelure. This one is interesting, because while the use of the M193 and M855 5.56x45mm projectiles (esp the M193) were decried in some circles as being cruel for their designed-in fragmentation-based wounding profile, this particular round did exactly that, but much more so. While all of the .308-caliber projectiles skirt the border of pi+ due to the sideways orientation they assume within the target, this one easily earns it, if not earning pi++.
      Hollow-point or soft-point ammo: There are innumerable versions of this, and from a GURPS perspective they are supposed to take the projectile from pi to pi+. The real bullets will certainly do this, if not more so, as calculated wound channels easily hit 2.0 to 2.5 with expansion ratios of 2.0 to 2.5 easily and commonly obtained. By the book, you’d do 7d (0.5) pi+. By my calculations, you’re looking at more like 5d+1 pi++. There are so many variants of this type of hunting projectile that picking one is a bit presumptuous. 
      M948 SLAP: Easily the most awesome thing fired out of this chambering. Designated the M948, it features a discarding plastic sabot (far right) wrapped around a 62-gr 5.56mm tungsten projectile. When all is said and done, though, you get 7d (2) pi- out of this, and the tendency for the sabot to come apart at the muzzle brake led some people to note that you should never shoot this ammo out of any firearm, ever. Was replaced by the M993 in service for some odd reason having to do with not having the troops barrels explode in their faces. 1/2D 400yds.
      Platforms

      Thompson Center Encore

      While some have created pistols out of .308-caliber cartridges (the Thompson models coming immediately to mind), by and large you’re looking at rifles here.

      Some notable platforms:

      M14

      The M14 was the first entry here from the USA, and was a very traditional-looking rifle. Wooden furniture and 22″ barrel. The thing weighs 9.2lbs empty, and about 11 lbs loaded, so you’re going to want to be strong. Highly jumpy in full-auto fire.

      FN-FAL

      The FN-FAL is the classic full-length battle rifle employed by pretty much every country but the USA that belonged to NATO. It sported a 21″ barrel and the classic 20-round magazine. Variants weighed between 9.5 and 13 lbs (that one featured a heavy barrel and 30-round magazines for use as an ersatz SAW.  Like the M14, it could beat you up pretty bad in full-auto fire, and some eliminated the feature. The rifle is over a meter long (43″).

      H&K SR9

      The G3 series was the Heckler and Koch platform for the 7.62x51mm NATO cartridge. It featured a 450mm barrel (17.7″) and was about 40.5″ long. A short-barreled version (G3K)  featured a 315mm barrel and 28″ length with the stock collapsed. Even the small ones were 9-10 lbs empty. Notable was the accurized and extremely expensive PSG1. Civilian shooters in the USA could try and procure the modified SR9 instead.

      SCAR-H or SCAR 17

      Three additional rifles that should be mentioned would be the SCAR-17, an up-chambered version of the SCAR rifle by FN (makers of the FAL). This gas-piston system is designed to be quite modular. The light version firing the 5.56x45mm cartridge did not find favor with the US Special Ops command, but the heavy version, the SCAR-H in 7.62x51mm did find some favor. The rifle comes in 13, 16, and 20″ barrel versions, and all versions are within a quarter-pound or so of 8lbs, empty.

      Kel-Tec RFB

      The final two are both bullpup-configured rifles, making up for the desire for a long barrel in a heavy-caliber rifle by putting the action behind the firing hand. The first is the Kel-Tec RFB, which appeared in roughly 2007. Gas piston, accepting FAL magazines, it comes in 18, 24, and 32″ barrel lengths . . . the last one capable of delivering enough velocity to hit 7d+2 at the muzzle, but dropping off into 7d+1 land soon enough that it’s not worth expanding the chart. The shorter-barreled versions are 8.1 and 8.7 lbs empty, while the “target” barrel length is 11.3 lbs. Overall length with a 32″ barrel is 40″ – as long as a full-sized G3 but with 15″ extra barrel. The carbine variant with barrel length equivalent to the G3 is only 26″ long. It’ll run you just shy of $2,000.

      Desert Tech MDR with reflex sight and suppresor

      The final entry is the Desert Tech MDR, which is either almost-available or just-available. A very, very expensive weapon when fully configured (and including a suppressor, which adds nearly $1500 to the cost, so YMMV). It features a 16″ barrel, 27″ overall length (more with suppressor, I think), and a $4,000 cost as pictured to the right! Caliber conversion kits are available, allowing 6.8SPC, .300 Blackout, and 7.62x39mm with a barrel change and mag insert replacement. Like the Kel-Tec, it’s a forward-ejecting system.

      Parting Shot


      The 7.62x51mm cartridge was more or less designed around “battle rifle” length specs. If you’re expecting a meter-long rifle that weighs the best part of 10 lbs, you are looking for an “efficient” version of the .30-06, which is where the specs originally came from.

      However, as they say, that was then, and this is now. If you start looking at 16-18″ barrels, or even 24″ out of a bullpup to allow close-quarter fighting and handiness (though at the cost of sight radius . . . which a good optic can probably address for you), then you’re into the 6d to 6d+2 range – and maybe a slightly smaller caliber, or the same caliber but optimized for a shorter barrel would do? There are a billion wildcat cartridges out there, and either finding or creating one that would fit the bill in a 16-18″ barrel would be straightforward. Still, the .308 is here to stay for at least a while, and there are a lot of platforms and cartridges to choose from.

      The GURPS rules for hollow point or expanding bullets in GURPS are pretty simple: you pick up one level of increased wounding modifier in exchange for having an armor divisor of (0.5), meaning that your projectile is really quite poor at penetrating armor, but pretty good at injuring people.

      So 2d+1 (0.5) pi- would normally average 8 points of penetration through armor, and 4 points of injury on an unarmored person. Against DR 4, on the average it would be blocked. Why one would fire off a pi- hollow-point is beyond me, of course – the example just shows how the rules work.

      A 9mm FMJ would be 2d+2 pi normally, and thus do 9 points of armor penetration, 9 points of injury, and 5 injury through DR 4. A 9mm hollowpoint would (in RAW GURPS) would punch through only DR 4.5 on the average, and do 13.5 points of injury against an unarmed person. Only one point (on the average) would punch through DR 4, resulting in 1.5 injury.

      A .45 ACP would normally do 2d pi+, and in hollowpoint will do 2d (0.5) pi++. So again, against an unarmored person, 7 points of penetration and 10.5 of inury in ball, and 14 in hollow point. Through DR 4, 7 won’t penetrate in JHP, but ball will do 4.5 injury.

      In any case, the RAW is simple.


      The Ballistic Calculator


      My ballistics calculator handles things a bit differently. It recalculates penetration based on the expanded diameter of the projectile instead of applying arbitrary modifiers. This can produce truly monstrous wound channel modifier (though GURPS caps at pi++), but also gives a nice, straightforward damage reduction that isn’t quite as harsh as the (0.5) armor divisor.

      Now, let’s look at three examples. A 1.3 expansion (typical of some .45ACP), a 2.0 expansion (which is typical of Jacketed Soft Point rifle bullets), and 1.65 (which works well for modern 9mm and .40 S&W that was engineered for large expansion).

      • A .45 ACP with no expansion has 2d with a 1.5 modifer. (7 points)
      • A .45 ACP wth a 1.3 expansion has 1d+3 with a 2.1 modifer (6.5 points, or )
      • A .45 ACP with a 1.65 expansion has 1d+2 with a 2.7 modifier (5.5 points, or -22%)
      • A .45 ACP with a 2.0 expansion also does 1d+2 with a 3.4 modifier

      A 6.8x43mm would do 6d with a 0.7 modifier unexpanded

      • The 6.8 with a 1.3 expansion would do 5d+2 with a 0.9 (21 to 19.5, or -7%)
      • The 6.8 with a 1.65 expansion would do 5d with a 1.2 (21 to 17.5, or -17%)
      • The 6.8 with a 2.0 expansion would do 4d+3 with a 1.5 (21 to 17, or -19%)
      So between soft and expanded, you’re looking at about -20% for effective hollow-points. That’s about -1.5 per 2d damage, regardless of caliber. If you want to account for soft bullets, it’s more like a (0.8) than (0.5).
      So a 9mm would go to 2d pi+, and a 6.8mm would be 6d-4.5, which is 5d-1 pi+.
      Against armor, it will tend to do a bit better than the RAW, but still worse than unarmored flesh.
      The (0.8) will be annoying in play; I’d tend to ditch it, but if you can quickly just increase DR by 25% before figuring penetration, you’re good. 5d-1 pi+ carbine bullet vs DR 12? It becomes DR 15, and likely on the average will do 1.5 penetration, increasing to a bit over 2 points of injury on the average. By RAW, it’s 6d (0.5) pi+, and DR 12 goes to DR 24, and will almost always bounce.

      Parting Shot

      This is for extreme realism fans, and even so, the modeling work required to pull this off is probably more than most people need. But the RAW really nerfs the penetration abilities of JHP bullets, making them devastating against
      unarmored targets, but utterly useless against any sort of armor. That’s true to an extent, but not as much as GURPS makes it. 

      The trade-off is a lower DR increase relative to RAW, but also just slightly lower raw penetration (which takes the edge off the larger wound modifiers when not using the granular, limited nature of the pi-/pi/pi+/pi++ scale.
      For games, the RAW is, without a doubt, easier. The math-heavy version makes for better comparisons where The Reloading Press is concerned. 

      The Reloading Press is an at-least-weekly feature here on Gaming Ballistic for 2016. Each week it looks at some interesting real-world cartridges and presents them with hopefully-useful information in GURPS Format.

      .45 ACP / 11.43 x 23mm

      The .45 ACP was designed and adopted between 1910 and achieved “final” approval in 1911, when mated with the winner of the platform competition, the now-legendary Colt M1911. Adopted as a result of reported failures to incapacitate the enemy in the Phillipine-American War (the Moro Rebellion) from both the .38 Long Colt and the .30-40 Krag. A bigger bullet with a bigger punch was requested, and this cartridge was modified from a .41-caliber cartridge then under current development by Colt and Browning. 

      The basic inputs will be driven from the classic load – the 230gr full metal jacket round that formed the basic projectile more than a century ago. Fired from a 5″ barrel at 250fps, this is in many ways the standard against which all other bullets are compared – if that standard isn’t the 9mm. And if it is, the proponents of the .45ACP are willing to fight them about it.
      Ballistic’s Calculator Inputs

      Basic inputs for the calculator are as follows, selecting 127mm for the (test) barrel length.

      INPUT
      .45 ACP
      Chamber Pressure 18575 psi
      Barrel bore 11.43 mm
      Case Length 23 mm
      Chamber Bore 11.43 mm
      Barrel length 127 mm
      Bullet Mass 230 grains
      Aspect Ratio 1.5 L/Bore
      Burn length 5.5 mm
      Projectile Caliber 11.43 mm
      Total Accelerated Mass 230 grains
      Expansion Ratio 1.7 expansion
      Output Stats

      The classic cartridge is the original one: the 230gr load which earns the standard GURPS stats of 2d pi+ when fired from the 5″ barrel of the Colt M1911. You can see that the half-damage range is healthy, and that barrel length starts to be substantial in order to eke out more energy from the round.

      Notes
      • The velocity is at the muzzle. The velocity with a 5″ (127mm) test barrel is tuned to match real-world data at 830 fps with a 230gr FMJ bullet. This is not the highest energy .45 available, but it’s the standard. 
      • The 230gr bullets have a straight-up pi+ modifier (AP modifier of 1.5) in my model; 185gr are 1.43 and 200gr is 1.46. So pi+ is the rule of the day
      Once you get past a 15″ barrel, you’re not helping yourself. At all. So in effect there are three practical barrel lengths for GURPS: 3.2 to 5″ are all in the 2d range. SMG barrels of up to 11″ will get 2d+1. And then carbine-length barrels of 16-18″ will do 3d-1. The intermediate 11-15″ range, while interesting from a GURPS perspective, seems to be a bit of a no-man’s land.

      The default original cartridge was a full-metal jacket round. The modern tendency for self-defense pistols tends to be Jacketed Hollow Point, or JHP. These can have some impressive expanded diameters . . . but not that much more than the .40S&W, which makes it a non-issue to trade higher magazine capacity for expanded diameter when dealing with modern rounds.

      Not that a 0.7″ to 0.75″ expanded diameter is chicken feed, and the highest expanding load is larger than that of the highest .40 . . . but only by 0.03″.

      Alternate Loads

      The load chosen for the original was the original. But there are some interesting and impressive hollow-point loads. 

      From a GURPS perspective, though . . . the best you can get from a hollow point is pi++. Now, that’s impressive, but you don’t need that much of an expanded diameter to get there, so the really high expansions, while great (perhaps) in the real world, don”t buy you much. From that perspective, the “ultimate” JHP is going to be the highest energy load you can buy that ekes out the full pi++ when expanded. That’s only about 0.59″ with the 200 and 230gr bullets, and 0.60 for the 185gr. All of that means that the bullets on the list below all qualify for a “good” GURPS JHP.

      Of the list below, the fastest 230gr load is 908  fps, the fastest 200gr is 982, and the fastest 185gr is 1019. These produce (including proper expansion multiples):

      • 230gr at 908 fps: 2d pi++
      • 200gr at 982 fps: 2d pi++
      • 185gr at 1019 fps: 2dpi++

      Recall my model accounts for the JHP not with an armor divisor (in this case a multiplier), but a damage reduction for raw penetration. This basically means that any shooter worth their salt will carry JHP rounds at the full 2d out of a 5″ barrel, and they basically all perform close enough to the same that you don’t need to specify which one you’re using.

      Not too many people seem to make high-energy FMJ rounds that aren’t mostly less than 100 grains, so cataloging them isn’t worthwhile. 

      Platforms


      M1991

      The number of .45ACP handguns is vast, vast, vast, but of course you have to start with the actual Colt .45 ACP, now updated as the Colt M1991. This venerable design is also built by a large number of custom pistol shops, such as Kimber, who adds plenty of quality at a reasonable price, and there are other custom shops that do fantastic work (for a high price). Les Baer, Guncrafter Industries, Wilson Combat, Ed Brown, and STI (whose pistols were given to Monster Hunter Owen Pitt as a gift). 

      STI Lawman

      These tend to be single-stack firearms of the original 7 or 8-round capacity. Larger capacity magazines can be found for those with suitably-larger hands. The Glock 21 held 13 rounds, and other double-stack magazines from 10 to 14 rounds capacity can be had for Sig Sauer, Para-Ordnance, and others. Some of these are available in cut-down versions with shorter barrels for concealability.

      In the SMG set, the Kriss makes a unique SMG designed from the ground up to be ridiculously low recoil, and the inevitable H&K SMG – the UMP chambered for .45ACP.

      And of course, the original .45 Thompson cannot be left out – both in “gangster” configuration with drum magazines, or the military issue SMG seen in Saving Private Ryan and other movies with stick mags.

      Thursday is GURPSDay, and after thinking about the concept of encouraging more Roll and Shout when doing Quick Contests last week, I ended on a cliffhanger saying that I thought there’d be a good way to adjudicate guns combat a bit faster.

      Not much about GURPS task resolution at its core is hard. Roll 3d6 under the target number. For skills, margin of success mostly doesn’t matter, because your choices tend to be front-loaded by design.

      What does that mean? If I want to chop a leg, or do a tricky blow that speeds past defenses, I declare it as part of the maneuver, and then it’s a yes/no did you do it or not, mostly.

      Obviously that’s not always true, and there are a lot of cool effects where Margin of Success matters – not the least of which is rapid-fire with guns, the very case we’re discussing here. Still, my guidance when I was writing rules was to encourage front-loading the decisions.

      In any case, the thing that takes the time in GURPS is – nearly always, in my experience – working out modifiers. That’s why the Dungeon Fantasy monster writeups are so cool. They list out a monster’s attack with the attack name, a flat skill to roll against. Sure, you can stack on a hit location modifier, etc. But usually you don’t. If a monster typically attacks the leg, it’ll be noted, and statted out for you. 

      The goal here is to make firearms combat as similar to that as possible, where the goal is to get things “close enough to right” that there’s a balance between differentiation on the character sheet and speed of resolution. 

      With that in mind, I’m going to have “penalty classes” and “bonus classes” with fixed values that approximate things that are usually done with a resolution of +/-1 to skill. The usual considerations will apply, but we’ll try and speed things up.

      If this offends, just stop reading. If assessing all of this is so trivial that your whole table does it by instinct, that’s awesome. But since one of the last games I played had everything from “I’ve never played in a RPG before” to “I’ve written books for GURPS” side-by-side, it might help.


      Penalties


      Modifiers to skill for guns are plentiful and stack up some of the largest penalties in GURPS. The biggest two offenders are range and target location. Range can be arbitrarily high and penalties start accruing for anything at 3yds away or more. Hit location spans from -0 for blazing away at the torso to -10 for shooting through an eyeslit in a helmet. Lighting penalties also range from 0 

      Simple Range, Location, and Environment

      To cut down the granularity and lookups, use the following simplified tables. They are somewhat intentionally vague. The -2, -4, and -8 penalty regimes are basically the Close, Short, and Medium range bands from GURPS Action 2 (the box at the bottom of p. 31).

      By and large, unless you’re dealing with characters with firearms base skills over 20, a good rule of thumb will be that a shot with net penalties (accounting for bonuses, below) eats up more than half the skill probably won’t be taken. In reality, people will often blaze away with net skill in the 5-7 range (6- being 10% chance to it, 7 being about 15%, and 8 being 25%). My experience is that PCs will usually strive for net skills of at least 12, but that’s not always practical or possible.

      Non-ideal conditions

      The goal here is to boil it down to three choices. Shooting inside a well-lit open room for the generic center of mass? -4 for range, no other penalties. Going for a head shot in a cube-farm? -4 for head, -4 for significant obstruction, for net -8. Between the eyes across a sports stadium in a storm? -12 for range, -8 for target, and -8 for the storm. That’s -28, and good luck with that.

      Note this chart makes shooting for the vitals and the head (which of course in 4e GURPS, but not casual vernacular, the “Face” or the “Neck”) indistinguishable. Yeah. The goal here is to find an intermediate penalty and generic effect for something similar to a vitals, face, or neck shot. Vitals is -3 and x3 damage. Neck is no effect from piercing. Face has knockdown at -5, and hits use the Critical Head Blow Table, etc. I figure an intermediate penalty, extra damage, and knockdown roll for all would probably be a good blend. But . . .

      If you despise the “Location” column and prefer the existing Hit Location and effects, just use them as-is. The key for the table above is that it’s fast and meets player expectations. If a player has memorized the location penalties and effects, boom. No time spent. 

      Rapid Engagement and Targets


      By and large the only other penalties that show up are 

      • Bulk penalties for moving and shooting or fighting in close combat. Use -2 for pistols, -4 for combat rifles, SMGs, and self-defense shotguns. Reserve -6 for full-size muskets, battle rifles, and sporting guns (long-barreled hunting rifles or shotguns used for bird hunting, skeet, etc.). While the usual penalty for rapid acquisition of targets is -2, using the bulk penalty instead is a good way to sweep up any sort of “my gun is moving while I’m trying to do stuff with it” or “I have to slew my weapon rapidly across the target” into one category.
      • Multi-target engagement is for pointing at more than one thing at a time. Two point targets on the same object, or two different targets are the same penalty: -6. Theoretically you can call it -6 for each target beyond the first, but in practice that stacks up so fast that doing more than two is impractical.

      Bonuses

      There are a few situational modifiers that give you bonuses, some of them can be quite significant. All of these assume a rapidly changing, chaotic combat environment. So while you can often be awarded significant bonuses for non-combat conditions (see Tactical Shooting, p. 9), that’s not what I’m talking about here.

      Equipment



      The other good stuff that adds to skill are things like laser sights and reflex sights. These adjust skill directly, so that +1 you get from a reflex sight isn’t something that changes from shot to shot. You always get it, so just increase base skill – if you can do this as a Conditional Add on an automated character sheet, so much the better.


      Maneuver Selection


      There’s really only one option here for ranged weapons: All-Out Attack (Determined), which gives +1 to hit. While that’s significant in terms of mathematical result (you’ve just extended your accurate fire range by 50%), in practice the measly +1 doesn’t offset the total loss of defenses. 

      Also, there’s another thing you can do to hit with another +1, which is to Brace the weapon. This is two hands on a pistol, two hands plus a sling for a rifle-type weapon. This is often only available if you Aim.

      Unikitty says never AoA

      To encourage the use of all of these, I’m going to wrap these up into one selection: Committed Attack: Determined and Braced. If you choose to do this, you get +2 to your skill, but suffer -2 to all defenses. You can take one step as part of this, or two steps but you get no bonus to skill. 

      No, it’s not realistic. If you’re doing this, by and large you’re not defending. This is clear in Tactical Shooting, and it’s based on real study of real shooters, who are not ready to fling themselves aside, parry a sword, or otherwise react to something crazy happening.

      It is, however, practical from an opportunity cost perspective. In GURPS the cost of losing your defenses is gigantic. To the point where I’ve heard it articulated that All-Out Attack is something you should never, ever, ever EVER do.

      So this tones it down a bit, but puts together things that often go together in practice: a determined, braced attack. Sure, you might not have the sling or two-hands for a pistol. But whatever. The point of this is fast.

      Aim and Lots of Aim


      Each weapon has an Accuracy statistic, which is added to your skill when you take an Aim maneuver. In practice, this is the way the monster penalties are removed, too.

      There are two ways to deal with this: note the actual Aim bonus for your weapon, and keep track of it. This obviously most consistent with published rules, and if you print out a character sheet using GCS or GCA, or even just look up your gear and write it down ahead of time, that’s right there on the sheet.

      The other is to simplify it and make generic categories. 

      • Pistols: +2 following an aim maneuver
      • Combat Rifles: +4 after an Aim. This includes shotguns, assault rifles, carbines, etc. 
      • Sniper/Precision Weapons: +6 after an aim
      • Recoilless Beam Pistols: +6 after an aim
      • Recoilless Beam Rifles: +12 for aiming

      Got all the time in the world and a proper scope? Can afford to pick your time to shoot? Double the figures above. Got Gunslinger? Add it every shot for pistols, add half for rifles. Just note that as an all-the-time bonus to skill, because that’s how it works in practice.

      Double Acc for lots of time? That seems like a lot, but you can usually hold aim for two more seconds for an additional +2, and scopes get +1 for each doubling of magnification, and common scopes give +2 (say, the x4 ACOG type scopes) or +3 (8-15x). There are even 30x type scopes available, which are almost +4. Computer targeting, which is probably available if you have effective laser weapons, can get pretty crazy too.

      If you feel it’s too high, just use +50% instead of x2 for beam weapons; +9 for pistols and +18 for rifles doesn’t seem wrong. The rest are quite possible, even routine.

      Rapid Fire


      The final category of bonuses tend to come from rapid fire. I’ve used a couple of really nice house rules for this one, the best of which is “bonus of half the SSR for shots fired.” This has a few advantages that I won’t go into here. But it produces values that look like the chart to the right.

      In practice, I’ve seen three rates of fire, using this rule or no. Single shots, three shots, and ‘full-auto.’ So you get no bonus for the first, +1 for the second. Full auto tends to be “military weapons with rifle cartridges” at +2, “SMGs and 3-rounds with buckshot” at +3 and “OMG gatling guns!” at +4.

      So just write down the bonus you get for whatever maximum rate fire you can eke out. It, again, makes things simple: Single shots and double-taps are no bonus. Three-round or four-round bursts are +1. Then you need to write down your personal value for “many shots.” That’s it. Yes, this ignores things like Fanning and other high-speed semi-auto stuff, but I’ve never seen those used in play. Others’ may have, so YMMV.

      This again takes the existing GURPS rules for RoF and tweaks them, but this one is for the better, I think. The progression above fits better with how GURPS calculates weapon fire spread.

      Posture


      GURPS posture penalties are really designed around melee fighters. It assigns a -4 to attack from lying down, and no penalty to attack while standing.

      Ranged modifiers require a bit more parsing. There are no bonuses or penalties for Attacking due to posture. Defenses are as-written. Target applies to attacks against the torso, groin, or legs (not skull, face, or arms) from most angles.

      So pretty much you can just simplify and say that shooting a non-standing target is at an extra -2 for normally unpenalized attacks, but vitals and head are the same penalty, so you might as well shoot head. That turns the three-stage hit-location into

      • -2 Torso on prone foe
      • -2 Arms on prone foe
      • -4 “Head” on prone foe, and don’t bother with vitals
      • -8 Skull on prone foe

      Being prone makes it easier to brace, but that’s not really reflected in the rules anywhere. I’d personally allow a two-handed firearm to claim the +2 for Committed and Braced without a sling while prone.

      Parting Shot

      This short checklist is designed to be fast and get you in the right ballpark. It’s supposed to blaze past the “fiddle” and get you to rolling dice. It’s a blend of generic difficulty modifiers and categories of “close enough.”

      This one isn’t fiddly realism. It’s a close-enough blend of enough divisions to provide distinction between skill levels and weapon types, with enough consolidation that the GM and novice players can not have to figure penalties for each individual attack. 

      Consider that for range bands, mostly players and bad guys tend to cluster in groups for range. “Punching in the face, with interspersed gunfire” is no penalty. Can close distance with a move at 15 feet or so is actually about the typical distance for low-light noir conflict. Within a small room? Also common. Beyond that tends to be “supporting fire” in the games I’ve played. So once you establish a range band, exceptions will tend to be only made for “crazy guy is running in to use the melee weapon he paid a lot of points for.”

      The rest? Few enough choices to matter. Distraction level/environment is like BAD (Basic Abstract Difficulty) from GURPS Action, and will tend to apply to everyone.

      Quickly, though, it should be as fast as the following. 

      • Range band (and that will tend to be ‘in close combat’ and ‘everyone else’)
      • Distraction and environment (open, moderate, hard, what are you thinking?)
      • Bonus: Maneuver (regular or committed for +2 attack and -2 to all defenses)
      • Bonus: Number of Shots (one, three for +1, many for usually +2 or +3)
      • Bonus: Aim (single bonus or double for all-the-time-you-need shots)
      • Hit location (torso, limbs, x3 damage, x4 damage/chinks)

      The first two (bold) more or less applying to everyone in the combat at once. The Aim option only applies to those that wish to burn a turn aiming. The rest are individual choices, and will tend to have favorite choices by player. Higher skill guys will tend to shoot for the vitals/head (-4) using three shots (+1) when they can, etc. Sure you can mix it up, but skilled fighters tend to be trained fighters, and training often says “do this this way every time for best effect.” 

      The key is to avoid analysis paralysis. Enough choices to be interesting, minimal look-ups and calculation (including ‘how far away am I from target X? How about target Y?’) in play. 

      A good rule of thumb here is if the net skill drops below 6-8, just switch over to suppresion fire, and roll vs. 6+RoF bonuses and force Fright Checks on targeted foes. PCs in my experience won’t shoot with skill less than 8, and frankly would prefer 10-12 if they can get it, and 13-16 otherwise!

      If by the time you get to the end of this post, your eye is twitching like Donkey from Shrek, go ahead and use the full-on rules. That’s what they’re for. But the level of abstraction above isn’t that high, and the number of choices has been – usefully I think – cut down to a bare minimum. 

      You can also employ variable resolution here. Particularly important scenes that had a lot of planning go into them, or are the climax of a long series of intel gathering, tactical planning, recon, and then execution can use the full-on rules, which will tend to maximize the players advantages in training and equipment and skill. 

      But for “someone pulls a gun and starts blazing away!” random violence, the quick-selection rules above are probably where you want to be.

      The Reloading Press is an at-least-weekly feature here on Gaming Ballistic for 2016. Each week it looks at some interesting real-world cartridges and presents them with hopefully-useful information in GURPS Format.

      .40 S&W / 10x22mm S&W

      .40 Flat-nose FMJ

      The .40S&W was invented after the 9mm bullets that were the standard issue for FBI agents failed to perform as desired during the infamous 1986 Miami shootout. The detals of that are interesting but not pertinent, other than it led to the trial and search for a replacement.

      Initially, a 10mm Auto was selected, butt that made for a large-frame pistol and packed a pretty significant whollop. Having personally shot a 10mm, I can attest to this – it’s a handful.

      During ballistic tests, it was found that a 10mm 180gr projectile loaded to about 950fps met the criteria for wound channel and penetration depth. That left a lot of air in the 10x25mm (10mmAuto) case, so downsizing it to 10x22mm let the package fit into a 9mm pistol frame. The cartridge debuted in January 1990.

      The basic inputs will be driven from a 180gr JHP bullet that matches the standard projectile initially developed for the FBI, selected as a higher energy load that expands well. This provides a healthy energy load . . . but not the most energetic available (which GURPS favors due to conversion factors).

      Precis – The Reloading Press weekly feature writes up the .40S&W pistol cartridge.

      Ballistic’s Calculator Inputs

      Basic inputs for the calculator are as follows, selecting 100mm for the (test) barrel length.

      INPUT
      .40S&W
      Chamber Pressure 34000
      Barrel bore 10
      Case Length 21
      Chamber Bore 10
      Barrel length 100
      Bullet Mass 180
      Aspect Ratio 1.8
      Burn length 3.81
      Projectile Caliber 10
      Total Accelerated Mass 180
      Expansion Ratio 1.78
      Projectile Load 1

      Output Stats

      Selected Gel Impact Tracks

      This cartridge is designed to be an intermediate in many ways. Intermediate in caliber between 9mm and .45ACP, intermediate in velocity between the 1250fps of the 9mm and the 800fps of the standard .45 ACP.

      This one is a 180gr projetile at 995 fps out of a 100mm barrel, which will do even better out of the 5″ full-sized pistol. More on that later, but here’s the chart showing how damage changes with barrel length.

      Notes
      • The velocity is at the muzzle. The velocity with a 4″ (100mm) test barrel is tuned to match real-world data at 995 fps with a 180gr JHP bullet. This is not the highest energy .40 available, but it’s pretty good, and within the original FBI specs, so it’s what I chose.
      • Out of a full-sized, 5″ barrel such as the M9 pistol (Beretta M92, or M96 when it’s in .40) there’s no real reason to use a 9mm in GURPS. More on that later.
      • The breakpoint for pi+ in GURPS is currently at 10mm/.40″. You can see that’s a bit generous, as the bullet modeled would be better at closer to +1 per die.
      Some more notes on barrel length. There are really two practical lengths for pistols here. The 3-4″ set will deliver 2d+1 damage. The full-sized pistol with a 5″/127mm barrel hits 2d+2. SMG barrels between 6.5 and 11″ long will get 3d-1. After that, carbine-length barrels will eke out 3d.

      The JHP with modern design is quite impressive, expanding in this case to 1.77x its starting diameter – and there are commercially-available loads that will expand to a full 2x the starting diameter, though they’re slightly slower. With the model the less-expanding and faster one is better, though. That will do 2d with  calculated 2.4 wound channel modifier. That won’t translate into usable criteria in 4e, as damage tops out at pi++. Still, most .40 weapons will hold 10-13 rounds in a concealable, accurate package that will do 2d pi++, getting the penetration of a 9mm JHP (2d) but the wounding of a .45 ACP JHP (pi++).

      Alternate Loads

      As noted earlier, the load chosen isn’t the only load, nor is it the “best” from a GURPS conversion standpoint. There are some very impressive loads in JHP (typical self-defense loads, but not military style stuff) in the table below.

      The hottest load will do 2d+2 even out of a 4″ barrel, expands to 1.65x (0.66″), and hits the right breakpoints to get 2d+1 pi++ out of a JHP. That’s about as good as you can eke out of a hollow-point round.

      Penetration in gelatin of various commercial JHP rounds

      In the FMJ category, there are some hot, hot loads out there that require  fully-supported chamber to fire properly. The Glock 22 and 23, for example, were partially supported, and could do nasty things with this ammo.

      But if you have the right platform, there are 155gr bullets that zip along at 1300fps (3d), and a very fast 135gr bullet at 1500fps that also does 3d, but is light-weight enough to drop from 1.2 to 1.1, which drops it out of any contention for pi+.

      Platforms

      Springfield XD(M) with extended mag

      There are a huge number of handguns chambered for the .40S&W – it rapidly became one of the most, if not the most, popular chambering for self-defense and law-enforcement weapons – at least recently and in the USA.

      Pocket pistols with a 3″ barrel such as the S&W M&P Shield, a few different Kahr pistols, and the 3″ or 3.3″ barrel Springfield XDs will hold 6-7 rounds in single-stack versions, and the XD double-stack holds 9.

      The more common 3.8-4″ service pistols blend concealability with 11 rounds in a flush-fit mag, and 15 or 16 in an extended configuration, which is easy on the grip but much less concealable. Glock 22s hold 15 rounds, while Glock 23s are 13.

      Springfield XD and Kahr (bottom) 3″ barrels

      Full-sized service pistols with 4-5″ barrels still only eke out 2d+1 until you hit the full 5″ barrel, such as in the Beretta M96.

      For SMGs, there are of course the usual offerings from Heckler and Koch – the MP5 and UMP. Sig Sauer makes a cool-looking one with an 8″ barrel, which is pretty common for SMG-length weapons.

      Finally, carbine-length weapons do exist, with barrel lengths that will tend to be in the 16″ range, but nearly anything in that regime will be identical for stats until one hits too-long barrels in which the bullet will have long-since past the point where the bullet is more slowed by friction than it is accelerated by expanding powder gas.

      Sig Sauer SMG

      Ultimately, the .40S&W is a nearly magical cartridge for pistols in GURPS. It hits all the breakpoints that GURPS has, allowing for good capacity, good damage, and excellent wounding.

      The (0.5) armor divisor that standard rules gives really tamps this down from a “wears any armor and you’re very well proteeted” perspective. If you use the decimal multipliers, though, it occupies a nice space. 20% more injury, about equal penetration, but modern JHP ammunition expands to feasome diameters, easily meriting the pi++ designation given by my system.