carbon build up with muzzle attachment

[radnur22]

i have a custom .308 with a phantom flash suppressor. when i first started working up loads, it would pretty much shot .5 MOA at 100 yards. 60 rounds later, the groups are now opening up. proper barrel break-in was done. i took the suppressor off to see if carbon was building up. there was carbon on the crown, but not an excessive amt. could this be the problem?

 

[James Jones]

The carbon build up on the flash hider could cause a problem f it were alot and causing some differant barrel vibrations or if it were extending into the bulletds path and contacting the bullet as it left he suppressor but this wold have to be ALOT of build up.

I would look at the actions screws getting a little more loose of tight after the gun has been fired and settling into the stock , it could aslo be the scope base getting a little loose or the suppressor geting loose.

this same type probalm was disscussed a little bit ago , we have to remember that some times some guns won't "settle down" and start shooting consistantly untill after a couple hundered rounds , generaly this happens with guns that foul barrel a little more than normal or have poorly fitted stocks