My Ruger PC9 had run like a champ...for the first 600-800 rounds. Then a couple stove pipes...then one after another. I had run it prett dirty, cleaned it with only a smidge of improvement. Poked round on the interwebs and read the extractor could be the culprit. Ordered an aftermarket one, dropped it in...back to perfect function. What a relief...it's a lot of fun and the rifle for the better half. It needs to run!