Reloading Press: .22LR

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.