Elephant Guns, ST and Rcl

[Icelander]

When using Douglas Cole's excellent spreadsheet to stat various rounds, the ST and Rcl must usually be assigned by comparsion to similar weapons already statted in one of HANS' publications. For the high-end of shoulder-fired weapons, such heavy hunting rifles as the Greener 8-bore, H&H Double Express, Rigby's Best Quality Double, Winchester 95 and H&H Best Quality Magazine are useful.

The absolute maximum in recoil is provided by the .700 NE, which is ST 15† and Rcl 9 from a 18.8 lbs. Holland and Holland double rifle. Only slightly less ferocious is the .600 NE, which is ST 14† and Rcl 7 from a 16 lbs. double from H&H.

The older 8-bore yields ST 13† and Rcl 7 from a 11.5 lbs. double made by Greener. Also at ST 13† is the A-Square Hannibal in .577 Tyrannosaurus, which has Rcl 8 from the 13.6 lbs. rifle.

Moving down to a .470 NE, we get ST 12† and Rcl 5 from a 14 lbs. H&H double rifle. The .500/450 Magnum Nitro Express gets the same numbers and it is reasonable to assume that the .450 NE and several similar cartridges would be around the same ST and Rcl.

Going down to lighter rifles and cartridges, we get ST 11† and Rcl 5 for both the .405 Win from a Winchester 95 (8 lbs.) and the .375 H&H from a Holland and Holland Best Quality Magazine Rifle (10 lbs.).

Now, however, we come to the anomaly which upsets my mental benchmarking and makes it hard to stat rounds which aren't presented in High-Tech or Pulp Guns. When we move away form H&H as a manufacturer, we find that the Rigby's Best Quality Double in .470 NE suddenly jumps up from the ST 12† it has in a H&H weapon and all the way up to ST 14†. That's quite a jump.

I'll grant that the Rigby weighs only 11 lbs., which is a whole three pounds lighter than the H&H weapons chambered for the same cartridge. It seems reasonable that this difference could affect MinST, because the lighter weapon will kick much harder. But why doesn't that affect Rcl? That remains Rcl 5, instead of going up to Rcl 6 as it should do if the lighter weight of the weapon is making it harder to control.

Also, even if going down by 3 pounds makes the weapon harder to control, should it go up to the same ST 14† as the .600 NE? The much more powerful .577 Tyrannosaurus only gives ST 13† from a 13.6 rifle.

I realise that recoil is more complicated than just calculating foot-pounds per unit of weapon weight, but it is at least instructive to naively examine the numbers before accounting for intangibles.

The 8 lbs. Winchester 95 fires a 300 grain bullet at just over 2,200 fps, which translates into 3,236 ft/lb or 404 ft/lb per pound of weapon weight. The 11 lbs. Rigby fires a 500 grain bullet at 2,150 fps, translating into 5,140 ft/lb or 467 ft/lb per pound of weapon weight. Meanwhile, the 16-lb H&H double rifle chambered in .600 NE fires a 900 grain bullet at 2050 fps, which means 513 ft/lb per pound of weapon weight. And the 13.6 lbs. Hannibal rifle in .577 Tyrannosaurus fires a 750 grain bullet at 2,380 fps, which translates into 753 ft/lb per pound of the rifle.

Obviously, the heavier bullets mean a much greater recoil than these energy figures would indicate, as recoil reflect momentum much more than energy. There exist several methods of calculating the free recoil and recoil velocity, of course.

For example, the .405 Win has 30.6 ft/lb in free recoil energy from a 8 lbs. rifle and the recoil velocity is 15.7 fps. The .470 NE from a 11-lb rifle has a recoil energy of 69.3 ft/lb and a recoil velocity of 20.1 fps. The .600 NE, meanwhile, has a recoil energy of more than 150 ft/lb and recoil velocity of 28 fps from a light 12-lb rifle.

Even correcting for an extra four pounds of weapon weight, it is still kicks significantly more than the .470 NE. As best I can determine, it would be at least 114 ft/lb of free recoil and 21.4 fps recoil velocity.

I don't know the exact recoil energy of the .577 Tyrannosaurus, but it's a lot higher than .470 NE as well. It's around 220 ft/lb, I think, and I'd guess the velocity is pretty high as well, but I'm too lazy to look up the powder charge and suchlike. Guess it's just over 30 fps. In any event, it's reputed to have the highest recoil impulse of any shoulder weapon, but is still only ST 13† from a weapon barely two and a half pounds heavier than the Rigby.

Is the higher MinST caused by any design differences between the Rigby and the Holland and Holland? If it is caused by the weight alone, ought not the Rcl rise to match? How heavy would the Rigby have to be for ST 13† to apply and at what weight does ST 12† start?