I'd say a Griz! I can outrun a Buffalo if need be. LOL!
(BP)

you'd be surprised BP. Buffalo are big and dumb looking but there are tons of stories from mountain men, almost being run down while on horse back. I think they said they can run up to 30mph over short distances.

MD, you'd be surprised how fast you can run with a Buffalo chasin you, and even faster with a Grizz chasin ya! And I live not real far from Buffalo N.Y. and them Buffalo's stink and cant run anyone down!
(BP)

A 400 gr bullet with 150 gr of Pyrodex, for one thing I would bet on a wack in the forhead with the scopes a lot of people use for I do not even want to think about the foot pounds of recoil. I would like to have a double transducer Texas strain gage with a logiteck read out on it. Pressure has to be up.
I calculated that a 400gr bullet needs a 1-30 twist to shoot its best [thats in a 45 caiber bullet] which means that it is not over length for a 1-28 twist and with the right velocity and barrel vibration could be accurate.
What appears to be possible velocity is according to the manual 150gr RS = 1800 FPS my estimation with BH would be 1900. I would want to do some pressure testing before I tried it.
muzzle= 1900 FPS 3200 FPE [Foot pound enegry]
100yds= 1720FPS 2630 FPE
200yds= 1555FPS 2147 FPE

Muzzle= 1800 FPS 2870 FPE
100yds=1630 FPS 2360 FPE
200yds=1472 FPS 1925 FPE

For comparison a .458 win. mag has 2350 FPS with 400gr bullet and 5075 FPE at the muzzle.
Kill at one end cripple at the other? Lee

Lee

The Bull Shop 45 cal conical is 1.12 inches long - drop that in a sabot you might have the length.... And possibly the Lehigh .458/300 grain HP - that is another long one...