The gun being fired in the left photo is of a reproduction Mortimer 12 gauge shotgun made by David Pedersoli from Italy. The gun is a good copy of the original but rather heavier. Although sold as a 12 gauge the bore is actually 18.3mm in diameter which makes it a 13 gauge. This is important as the wads to be used in the gun must be of the correct size to be the right interference fit in the bore,
The means of ignition for this gun is the flint. On pulling the trigger the cock holding the flint is thrown forward against the frizzen face, As the flint scraps of very small pieces of hot metal from the frizzen it flies back to open the flash pan, exposing the fine black powder that is ignited by the shower of hot sparks.