Reloading Press: .600 Nitro Express (15.7x76mmR)

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.

.600 Nitro Express (15.7x76mm)

The .600NE is an “elephant gun” cartridge introduced in 1903, and was the largest round used in the “heyday” of African safari big-game hunting. It’s a gigantic round (only outsized by the .700NE in this lineup) requiring very large and heavy weapons (13-20 lbs) to carry.

It’s large, very powerful, and not well engineered relative to more modern weapons (no one should expect otherwise – it was a 1903 answer to a 1903 question, and more modern bottleneck rounds can penetrate more, be more accurate at range, and be fired from a more robust, modern combat platform.

But very few will be quite as pretty. The rifles that shoot such a beast (such as the H&H Royal) are spectacular instances of a gunsmith’s art.


Ballistic’s Calculator Inputs

Basic inputs for the calculator are as follows, selecting 559mm for the barrel length. That’s on the shorter end of the usual range for such a rifle as produced by H&H; so few of these guns exist that it’s hard to get a truly “representative” value for such a bespoke weapon.

INPUT
.600 Nitro Express
Chamber
Pressure
40000 psi
Barrel
bore
15.7 mm
Case
Length
76 mm
Chamber
Bore
15.7 mm
Barrel
length
559 mm
Bullet
Mass
900 grains
Aspect
Ratio
2.5 L/Bore
Burn
length
39.7 mm
Projectile
Caliber
15.7 mm
Total
Accelerated Mass
900 grains
Expansion
Ratio
2 expansion
Projectile
Load
1
Output Stats

The output from a notional double-rifle with 22″ barrel.

Notes

  • The velocity is at the muzzle. The velocity from a 22″ barrel was tuned to 2000fps with a 900-gr solid bullet. 
  • With damage as high as it is, I didn’t do the point-by-point barrel lengths, since the difference between 10d and 10d-1 is in the “who cares” range for most lengths, but since one of the questions that has come up is which does more damage, the .600NE or the .700NE, I did do fine-grades around 10d

Alternate Loads

These monsters are mostly hand-built anyway, and can cost $50-300 per round. Of course, with what the platforms cost ($20,000 isn’t crazy talk, nor is $120,000), and trips to Africa for safari (which is where such weapons are mostly used) being $10,000 more, spending a grand or two for ammunition isn’t going to break anyone.

But by and large, you fire gigantic solid projectiles out of these guns, witness the .700NE compared to a .45ACP to the right.

Platforms

There are basically two platforms that you will use to launch this monster. A ridiculously well-made custom rifle that will likely cost you thousands, tens of thousands, or even hundreds of thousands of dollars, and weigh 13-18 lbs to boot, or a custom cut-down pistol that even Hellboy would cock an eyebrow at, though it would be an approving one, I suspect.

The classic .600NE is a double-rifle, basically two rifle barrels side by side, designed to give a rapid follow-up shot against a charging cape buffalo, bull elephant, or armored division.

These rifles are often heavily decorated, worked in gold or silver, and use only the finest woods for furnishings. It is not unusual to see the big-bore offerings go for $100,000 or even more for a used one.

For pistols, it’s really a matter of an exercise in gun design and “you can do it, but why would you?” than any real practical methodology. The weapons (two featured prominently in internet pix) are gigantic, require two hands to hold, much less to shoot, and the recoil would be spectacular. 

As you can see, these firearms are more of an engineering exercise when compressed to pistol size than anything else. While I’m sure there are RPG characters somewhere who would want to carry one, a short-barreled rifle format would be not much larger and at least give three points to brace (and injure yourself) instead of two.

Nonetheless, it can (and has) been done, and has been, with the T/C style pistol having a 14″ barrel and thus hitting for about 9d damage.

Comparison: .700NE


I’m not going to work this one up in detail. Suffice it to say that the 1000gr projectile at 2000fps is quite a bit larger in bore (though shorter; it’s a puny thing from an aspect ratio perspective), which mitigates to a large degree the increase in energy from the larger mass. It’s within a point of damage (a tetch higher) of it’s smaller .600NE cousin.

GURPS formally gives both cartridges 5dx2 pi++ damage. GURPS gets it right.

4 thoughts on “Reloading Press: .600 Nitro Express (15.7x76mmR)

  1. Is the Van Horn pistol a single-shot? I'm trying to figure out where you put the banana bullet…

    The attraction of pistols is that they can be managed single-handed, if you find yourself hanging off a ladder/car/rope/helicopter or holding a horses reigns/steering-wheel/gal hostage while you shoot.

    Not that those brutish pistols can be managed by normal people one handed or two, but the Inhumans in a Monster Hunters game would should be able to handle them. Does your formula guestimate a MinST?

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