nah im a freak about keeping it clean... i clean it every time i go out and shoot...
i havnt switched ammo, but i am getting a few more "weak" rounds than the last brick that i got... one was so bad that i could JUST hear it go off and it dropped 10 inches in 20 yards... i was bench resting it and was dead on the target, and it allmost hit the target below it lol... after that i checked the barrel for anything that may have been stuck in it (found nothing) and then fired some more.... maybe its just some bad ammo that i got...
what do you guys buy in bulk that dosnt cost alot and shoots good? right now im using winchester super X 40grain and its allright... (well the first box was lol...) im in love with the cci stinger ammo, but its alot of money for just blasting away...
one more thing... one day i lent my friend my .22 and he went shooting with it, no problems... and being a nice guy he cleaned it for me before he gave it back

but i allways clean it pulling the brush thru the barrel from the action, and from doing so many times like that i have bent the brush bristles back... when he did it he pushed the brush from the action down the barrel, and he said that he had to push hard to get it down... any idea if that could have messed something up? i dont think so, but you never know...