I've shot thousands of rounds through 10/22's and had only two problems. 1) yellow jackets-the weird shaped bullet doesn't feed well in the auto loader and jams. They are one of the VERY best 22rounds by performance though. 2) when prairie dog hunting or ground squirrel hunting (3-4000 rds/day) any bullets w/ the "black/grey" finish or wax or lube or whatever it is gums up the action pretty bad.