My dad recently found his old Ruger 10/22... He's not much of a "gun guy" so I took it home with me to give it a quick look over. I wanted to make sure he had a FUNCTIONING firearm in the house. The rifle was in superb condition on the outside but when I tried to cycle a full mag the rounds failed to eject.
I took it apart and found that the extractor spring was stiff as a board and covered in rust along w/ the extractor itself. I soaked the spring and extractor in Hoppes #9 for a few minutes, whiped them down, and put it back together... Problem solved! (Also added a new bolt buffer, extended mag release, auto bolt release, and polished some of the parts
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Anyhow, I'm sure this is NOT your problem, but if all else fails check the extractor. I seriously doubt you have any rust... but it wouldn't hurt to give it a look.