Only difference I ever actually noticed was on sidelock hammerguns, breechloaders and muzzleloaders. As Toby said, the right barrel is usually fired much more than the left. This is manifest in a weakened spring on the right lock after many years of use. Boxlocks should be subject to the same thing but, since opening the action is what (usually) cocks the hammers, you don't feel the difference in the strength of the two springs as easily as with external hammers which are cocked individually by hand.
I have cut a piece off a wooden clothespin and wedged it between the leaves on the right lock spring to strengthen it enough to make it reliably ignite the cap on original muzzleloaders. Shabby fix, but it works, and if done properly it stays in place. I guess it's no worse than shimming the hook with feeler gauge and loctite.
Stan
Last edited by Stan; 06/30/10 06:21 PM.
