I have lots of targets here at Thorn Hollow. The cost and availability of AR 500 would severely limit the number of targets I can deploy. My centerfire targets are mostly 3/8" thick mild steel and I have a velocity limit of sub 1,800 fps. I still get some dimpling with loads near that upper limit if the targets are to close, but not cratering.
1/4" mild steel is limited to .22 shooting.
I have a set of AR 500 swingers I bought a few years ago for use with jacketed and hot cast stuff. Two each of 4, 6, 8, 10, and 12" gongs. Just not as much fun as knock downs. These came with belting straps that far outlast chain. Do you ever wonder what championship caliber, (pun), shooters your friends would be if the bullseyes were made of chain, or 2x4s, our steel fence posts, or rails, or anything that is where you don't necessarily want a bullet to strike?