Did some experimenting at the range with a 1/4" steel plate at 300 yards. The .30-06 blew through leaving a hole that looked like it was drilled with a very dull bit (significantly increasing my respect for WWI tankers). Even the .223 almost went through leaving a crater and a big nipple on the back. On the 1/2" plate the .30-06 left a big crater but didn't go through, bulge on the back. The steel is A36, left over from some CNC plasma cut sheets. Is there a way to harden this? Some of the target makers on the Net refer to AR500 steel but my local metal shops either don't know what it is or don't carry it.
Thanks. Steve.