I have some 1/4 inch stainless steel plates that were left over bits from making an anchor roller assembly for a big sailboat that hit a harbor wall and bent the original one. So I thought that material would make nice targets. Before I cut it into shape I though I would fire a couple of test rounds at it at 250 yards and see how much of a dent the 223 WSSM would leave in it. Well turns out it didn't dent it at all ..... but punched straight through the plate .... back to the drawing board.

AR500 steel is the minimum I would use for shooting steel with a rifle cartridge. The 1/4" stainless may even be light for pistol cartridges IMO.

Chris

FMJ’s? If so then yeah, every single time, lol.

Nope sierra game kings in 55 grain

Well then, hope that boat never hits anything!!

Try a heat treatment. What have you got to loose?

3/8" AR 500 is minimum for center fire rounds.
3/4 plate will stop most rounds but will get cratered up pretty quick.

The SS you have will make great targets for muzzleloader fired roundballs, and pistol cartridges, but not much else. Even the AR-500 will not stand up to high velocity rounds at close range. I think they say velocity below 2500 at impact, you can check the websites selling it. One of my plates, 3/8" AR500, got 4 holes from my 6mm Rem before I realized what was happening. It was at 75 yds at the time I think.