I have shot at a free standing 8" plate made from T1 steel that was 3/8" thick. The plate was raked to the rear about 15*. The round I used was a 165 gr BTSP Hornady shot from a 30-06 at 2900 ft/sec. Hot knife through butter is an apt description. Range was 100 yards. I saw a piece of 120 pound railway steel with a 375 H&H sized hole through the flange. Eeek!
Be careful, my friend.
