My early 1950's 12g Boswell box lock double gun has a light primer strike in both barrels, but only on about every 3 or 4 cartridges in each packet. I've experienced the same issue with a couple of brands of factory ammo where the primers appear to be flush with the base of the cartridge ie. not sunken in.
I've has both V springs replaced recently and the gun is not off face. The gunsmith would have cleaned the action when he replaced the springs.
The firing pins protrude enough to strike the primers when extended.
I'm confused as to why the pins strike the primers with enough energy to fire and also show a decent indent on the spent cartridge, and with the same ammunition only just strike the primer with hardly any indent at all?
If the pins or springs work most of the time, what can cause the odd misfire using the same ammunition?
Any advice would be appreciated.
