I just shot the 8" gong at some BLM land in the Perris area (met a couple of other Calgunners in the process too). I shot my Garand M1, a Marlin 30-30, my AR15 pattern rifle and my AK pattern featureless rifles and the target stood up to each caliber fine.
You definitely can see where the rounds hit, but there was absolutely no damage to the gong. I don't have a rangefinder, but I know I set it at least 100yrds.
I just want to let everyone know TheTargetMan sells a quality product. Thanks TheTargetMan!