I have a two hundred yard rifle range and I try to maintain it every three weeks if I shoot once a week on the rifle range. I have some targets at one hundred fifty yards and one hundred seventy-five yards. I use AR500 steel that will handle cartridges up to and including 308Win. The steel will last forever, but painting is a necessity so the steel will not rust. If you have enough property to have a safe shooting range, I highly recommend steel over paper and cardboard targets. If you need any suggestions to set up an outdoor range, I would be glad to share my experience. You can leave a comment on the website.