Ben Towe: Probably more deer were killed with the old 44/40 than any other round except maybe the 30-30. The 44/40 had a 40 grain charge of black powder but the velocity was higher shot out of a carbine versus a pistol. Custer- in his book my "Life on the Plains" spoke of using just a plain old 1860 Army to ride up beside a buffalo and shoot it at point blank range.
I don't know what it is about that soft lead ball but it seems to defy logic in how it kills. The foot/lbs of muzzle energy used with most modern arms don't seem to apply.
so....I'd say at a VERY close range with a 40 grain charge, placed where it doesn't have to plow through a shoulder- should be okay.