text: The rails fit my handguard just fine. Screws are long enough, inserts are the right size, and the rails have the little circular feature to prevent them from moving around. The problem is that none of my accessories fit the rails. It's like they're too narrow. I tried an Atlas bipod with the quick release and it doesn't tighten up. Neither do my Magpul forward grips. Spend a little extra and get quality rails.