I got a used disc from a farmer that wasn't using it anymore ($0). Welded chain on it myself and hung it from chains in a frame that I built from scrap treated 4x4's. I've shot it from 550 to 900 yards with everything from 223, 264 win mag, 7mm rem mag, 300 wsm
......etc. etc. It holds up awesome, and I put clips on the chain links so I can unhook and put it in the polaris if I need to take it down. My range is on my own property, so I just leave it set up and take a can of paint with me - when I'm done shooting, I hit it with a coat of paint for next time. Once in a while a cow uses it to rub on, but it seems to be holding up well so far.
A blind flange would also work well with holes already in it to hang chain from (if you don't have access to a welder).