My marlin 60 .22lr has been acting up latley. I have cleaned it spotless and oiled it, but about 30 shots later it starts to fail. Misfires, no cycling, and inconsistant sound. I don't know why the sound is inconsistant because all shots hit the target and somtimes it cycles through it. It is not bad ammunition either, they are brand new federals and I have also used them before, it was also doing this with a new pack of thunderbolts. I know weather cannot be affecting it because I have shot in colder weather for a couple hundred rounds and it hasn't done this. I was wondering if you have any ideas of what could be wrong. I also checked for a bulging rim. There is none.