OK. Let's get technical. More moving parts then you imagine on a Flintlock. While the side plate incorporates a "lock", or sear to hold the hammer back the name is a misnomer. and a lock is a correct name for the breach plug, or as on a modern arm a bolt, trapdoor, falling block. rolling block. Here is a list of moving parts on a Flintlock. The cock, vice screw, upper jaw, flint, frizzen, frizzen spring, mainspring, tumbler, bridle, sear, sear spring, and that doesn't count a ball mold, or needed ramrod to operate the gun/rifle. Of course a percussion arm has a fewer parts, but still far more then two.