Pure lead cannon balls does sound like a wise first step here. Appreciate the input.

I did figure out what the foot pounds energy, momentum and Taylor KO will be (using the standard calculator that does NOT measure metplate). If the pure lead ball weighs 605 grains and it flies at 1525 fps (which I am confident I can achieve or exceed):
Energy: 3123
Momentum: 131
Taylor KO: 95

And with that solid RB "metplat" it would be a snot knocker for sure.

http://www.icm.cc
transforming ideas into reality