Took my trusty old MK II to the range today after installing my new VQ Exact Edge extractor. I had had a little problem in the past with Winchester M-22 .22 LR ammo, which I had bought a pretty big bunch of (3000 rounds). I would get the occasional stovepipe, in both my 10/22 and MK II. I installed VQ extractors in both guns. Went to the range, fired at least 200 rounds between the two using M-22-not a single stovepipe, not even one. Hey, for an investment of maybe $15 for the two, I think it was money well spent. Both were easy installs, putting the MK II back together, a PITA, but if you have a MK II you already know that. I'm a happy camper.