Calculating the force of a BP bullet.

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Aries-

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im trying to figgure out if useing my .45 caliber rigby will be enough to shoot bear or moose if i ever get the chance.

i know people say .45 is to small. but most .45 caliber guns use a rather small bullet, the one im useing is 527 grains, quite large in comparison.

anyone got some calculations that i could use. or know if it would be big enough to down a bear (i would assume so im thinking the bullet would knock a large deer off its feet as its long and when it hits im sure it will bend and tumble as it enters the body. )
 
You should chrono it and calculate the muzzle energy and compare that to known rounds. Some will disagree about muzzle energy being a good indicator, but it's easy to calculate if you know the velocity and mass.
 
Standard formula for energy is:

(gr)(v2)/450240=ftlbs

I can't figure out how to superscript velocity squared, so in words:
bullet grains x square of velocity in fps. All divided by 450240. Results in Foot/pounds energy.

Example: 527 x (1200fps)(1200fps)/ 450240 = 1685.5 ft/lbs
 
from what i have read in the long ranbe muzzle loader forum, the general FPS for these is 1200-1400FPS.

so its from 1685.5 to 2294 ft/lbs by those calculations.
 
A 527 grain bullet will get plenty of penetration. I'm one who feels .45 is too small, but with bullet weight like that, you don't need to be worried. At the low velocities that muzzleloaders deliver, energy isn't all that important as long as the slug has enough momentum to penetrate.
 
i looked in the hunting regs in this area. and they really dont say much about whats needed to kill a moose or bear. just gives min guage and shot size if useing a shotgun.
 
Maybe this will help

That is basically a 45-70.

If you use a bullet that isn't too soft, it should go through and through either moose or bear - even if bone is hit. It is understood that a flat nosed bullet works best as it causes more trauma.

You don't need an expanding bullet here - a good, tough bullet is called for as well as good shot placemnt...
 
its a pointed flat nose bullet. has a bit of a point to it and a flat nose. and about an inch and a half long lol.
 
Gotcha

I would suggest trying wheel weights if you're casting it yourself - that would be sufficiently hard - if it shoots well for you.

Even a softer alloy should be fine - just that you'd want to avoid shoulder shots - especially with the bear as it could deform enough to limit penetration - unlikely but still quite possible.
 
If you so choose Aries, you can put as much powder as you want (within reason) under that long bullet and have the ballistics of any of the various lengths of cartridges which were used in the .45 Sharps, and I wouldn't feel under powered taking a 45/110 Sharps after bear or moose. I shot through both deer I killed with my .451 last fall. The 550 grain bullet and 80 grains of Swiss 3f I use in it may be overkill on deer sized animals but they sure stayed shot! When I was working loads up for it I shot about 40 or so rounds with 95 grains of Swiss 3f. The recoil was "interesting" off the bench. I probably wouldn't notice recoil while hunting, though, I never seem to anyway. Your Gibbs would make, in my opinion, one of, if not the best choice for a muzzleloading bear and moose gun.

Steve
 
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