Sure cleaning the bolt wont hurt but i dont believe thats the issue. i would say you need to get some lapping compound and and a good cleaning kit and see if that doesnt help. clean the bore with the cleaning kit first then try using the lapping compound then clean it again. i would almost guarantee thatthis will fix it.If not see if a local gun dealer has a air guage to test the rifling and the bore. Also what brand of ammo are you using.