I have only fired about 60 rounds through it. It was used when I bought it. I don't reload so 120 a-max and 129 sst are the only ones I've used. It liked the 129 sst Hornady. No... it is a 0 moa rail on it. I only shoot to @ 300-400 yards so that was all I needed. I'm selling it to fund a new 6.5 CM ER Shaw mark VII.