Just received my replacement XM-18, due to the first one having terribly bad lock stick. Not without effort though. The dealer basically insinuated I was retarded and didn't know what I was talking about(at least that's how I took it). He seemed to think I was bothered by some dirt on the lock face, when in fact I really don't care what the lock face looks like. However, if there is visual marring *and* it has massive lock stick, well now we have a defect and a problem. He still claims he flipped it for an hour with no lock stick, which is either an incredible coincidence or an outright brazen lie. Anyway, in the end he entertained my complaint, and remedied the issue adequately. So B+/A- rating. The new one feels fantastic, lock effortlessly disengages, and wouldn't you know it, the lock face is free from imperfections. Hollow re-grind town, tally hoe(I will never financially recover from this)!