I've had a Ceiner .22 conversion for many years, but never put a whole lot of rounds through it. There's a local pin match that allows any center fire pistol, pistol caliber carbine, or rimfire rifle or pistol...and I was thinking of trying it using an AR with the conversion. So, I went to the range today with one of my ARs, the conversion, and a few boxes of ammo to try, along with my Brownells/BDM .22 conversion mags which I also hadn't bothered trying out yet. First was Federal bulk pack from WalMart. I ran 4 mags (of 10) of that without any trouble. Then I tried Remington Golden Bullet (also WalMart bulk pack). I had trouble with several of the first ones of those not wanting to fully chamber. Then I tried CCI Minimags, and had the same problem. I went back to the Federal, and didn't have any chambering issues, but started having ejection failures. The empty cases would extract, but then get caught up in the conversion bolt instead of ejecting. I gave the conversion bolt some extra lube before getting started, so I know insufficient lubrication wasn't an issue. I'm guessing the main problem is the chamber needs a good cleaning. I don't think I've ever done more than run a bore snake through it.