How's the rifle failing? Does it fail to extract the fired round, fail to feed a fresh round from the magazine, jam the next round into the breach face, or one of the 25 others ways they can jam.. I doubt the magazine spring is the problem. A dirty action is very possible as these tend to be quite dirty rifles. My guess would be a bad extractor/spring or a rough chamber.. Have seen a couple with weak recoil springs that had problems also.. As always in any magazine fed weapon the mag has to be checked out. But the Ruger rotary mag is one of the best... More info and perhaps we can get a better defined response.. gunnut69