I see a lot more misfires with autoloaders. Probably because everything in their mechanisms has to be tuned and in harmony so closely. They're usually light strikes, where the primer is lightly dented and does not fire. In 99% of these cases the same shell that misfired can be fired the first time in a fixed breech gun. I agree with Chuck that the auto is probably closer to the minimum necessary to fire the primer. They are trying to keep the resistance to the breech block traveling rearward at a minimum to facilitate reliable ejection and feeding. Remember, it is the breech block moving rearward that recocks the hammer each time it cycles. The fixed breech gun can utilize stronger springs than are actually necessary because it is not limited except by the force required to recock them when opening (or closing in some cases) the action. IMO, the extra strength in hammer springs in fixed breech guns is a "just to be sure" measure. Remember which genre of shotgunners almost never use autos .............. those with big money riding on a shot. Pigeon shooters. NSCA competitions allow two misfires, or gun malfunctions, in a round of 100 before it costs the shooter a lost bird. Not so with flyers.
It stands to reason that less force should be required than with a percussion cap. The p.cap has to be forced down upon the ring of steel at the top of the nipple with enough force to detonate the fulminate. With shotshells, not nearly as much force is needed by the firing pin to make the very small indentation in the primer necessary to fire it.
SRH
