Wouldn't a rebounding hammer be unsafe on a percussion shotgun, as you want the weight of the hammer and spring sealing the nipple and cap at the instant of peak pressure?
This should have been rather obvious & I totally let it slip right past me. By a similar token rebounding hammers are I believe generally considered undesirable on high intensity cartridge guns, as a Dbl Rifle. In this case a pierced priker is much more apt to occur if the firing pin doesn't remain in the primer under pressure. The use of a rebounding hammer is mostly confined to breech loading shotguns, or a few low pressure rifles.
