Shadow was talking about carbon build up with loads and it reminded me of a common problem with bullseye shooters. Larry Carter came up with a fix which I'll paste from his instructions on my Hammerli, but I find it applies to just about every gun I shoot. The problem centers around failures to feed, etc. Keep in mind the caliber mentioned is .22. I upgrade the size of the chamber brush just like with the .22 when cleaning all calibers just to eliminate chambering issues.
Solution: Have you cleaned your chamber?
If yes, have you done it correctly and thoroughly? 9 out of 10 feeding problems can be remedied by cleaning your chamber. When cleaning your chamber, use a .25 caliber brush bent in the shape of an L. Twist the brush to clean. Next, spray Brake-free oil on your patch and pull it through barrel. When the chamber is clean, you should be able to remove the slide, stand it up on end and drop a round into the chamber. If the round has to be pushed into the chamber, continue cleaning and/or send your pistol in for service.
Solution: Have you cleaned your chamber?
If yes, have you done it correctly and thoroughly? 9 out of 10 feeding problems can be remedied by cleaning your chamber. When cleaning your chamber, use a .25 caliber brush bent in the shape of an L. Twist the brush to clean. Next, spray Brake-free oil on your patch and pull it through barrel. When the chamber is clean, you should be able to remove the slide, stand it up on end and drop a round into the chamber. If the round has to be pushed into the chamber, continue cleaning and/or send your pistol in for service.