i have some 1/2 " gongs,depending on the quality of the steel they will hold up to must jacketed bullets.cast should be no problem at all provided they are not hardened.i have some laser cast 525 grn 50 cal bulets i shoot out of my 50 alaskan.they will shoot thru both sides of a kubota tractor bucket the steel was prob,1/4" each side 5 1/2' apart.
my little brother is a welder at a garnet mine,he gets me steel scraps of some type of hardened steel,1/2 of this will stop fmj bullets at 25 yds.it dimples them pretty good but no one has penetrated one yet.some of the steel is 1" thick.i have built quite a number of them.the method that seems to work the best is to hang them from heavy links of chain.i weld 3 or 5 links to the back of the steel one each side then weld it to some 1/4x1 1/2 angle.this lets the steel swing freely but also hangs at a slight angle.the slight angle helps to reduce the eveny of lead coming back at you.kind of directs it downward.also makes a real nice ring.i built a bunch for our gun club,they work real well until the buggers shoot the chains off.we lag the angle to the bottom of the target board,if they shoot off the chains i just unbolt them and bring them home to weld them up.when i shoot with my sons i make them wear shooting glasses,always a good idea especially with the steel.good luck with them,adker
