The round I had was called the 243 Super Rock Chucker, which was basically a 6mm-06AI. Although it was a 1:10 twist it would shoot 105 Amax at 3500fps but it was a laser with 75gr hornady hollow points at just under 3900fps, it would blow up 58gr bullets if I pushed them faster than 4475fps.

My brother shot a doe antelope at 445 yards with it with the 75s and a absolutely flattened it. If I had another one built I would use a 1:8 twist and not mess with light weight stuff just shoot 105gr + bullets and have a really antelope hammer. I did kill one doe antelope with it shooting 105 amax at fairly close range and laid her down after about three steps.