80 grains of Pyrodex RS and a patched roundball will blow right through a deer most of the time. In fact I had the experience of shooting one deer at 80 yards, blowing through that deer and killing a second deer behind the first deer. I had plenty of tags to cover the incident, but it gives you an indication of the power of a roundball.

I like to get them quartering away broadside, and tuck that behind the front leg, through the lungs and into the other shoulder. The deer usually drop right where they stood or make about 15 yards, but seldom go further then that. Also you get a good blood trail.