My Ruger 10/22T that I purchased new is a jam-0-matic. Finally had a gunsmith look at the rifle. The extractor is such a poor fit that it never engages the rim. The next time you clean the rifle, take out the bolt. Slide a 22 case under the extractor and see if there is a tight fit or if you have plenty of space. Those people who have reliable 10/22s must have properly fit extractors. Finally sent my bolt back to Ruger and asked that they correctly fit the extractor to the bolt. As the rifle was shipped, the cases were simply blowing backwards out of the chamber. After a magazine or 2 the jamming rate approached 50%. I tried every sort of ammo, new after market extractors, new barrels, etc. I tend to like Rugers, but 3 of the 4 Rugers I've recently purchased had to be sent back for repairs. Someone appears to be asleep at the wheel.