quote:

Originally posted by Expert308:The timing of the appearance of the problem is suspicious, but it doesn't make sense that putting a can on the gun would cause that kind of buildup, so I don't know what actually caused it. A tiny flaw in the machining in the barrel (rough spot) maybe?

The whole incident kind of ruined my faith in that gun and it's been a safe queen ever since.

Part of the reason a can works so well is it reduces "secondary recoil" that is caused by the gas jet leaving the barrel behind the bullet (think how a rocket motor works). This is all fine with a bolt action or similar. But when shot from a semi-auto, that pressurized gas in the can forces gas (along with crud) back down the barrel as well as out the muzzle. This gets the action filthy much quicker than when shooting non-suppressed.