SNAP CAPS AND DRY FIRING

LIGHT GUNSMITHING

- Gil Sengel

The subject of snap caps is one that seldom comes up among shooters today. Mentioning the term “snap block” just produces blank stares.

As one might guess, a snap cap is a cartridge-shaped device that fits in a gun’s chamber and cushions the firing pin when the firing mechanism is released, or “snapped.” But why would anyone want to snap an empty gun? Good question. Yet on countless occasions, I have watched people at a used gun rack pick something up and work the action, snapping the gun each time the action was closed – all of this while standing within spitting distance of a sign reading “DO NOT DRY FIRE USED GUNS.” This is why few dealers put expensive used guns out where customers can get at them without supervision.

The reason it’s not such a good idea to dry fire any gun is because of the damage it causes, which is cumulative. Centerfire bolt guns are probably least affected, because the force of the mainspring is stopped by the cocking piece slamming into the bolt sleeve. Surfaces are fairly large and will take a lot of pounding, but the shock transmitted down the firing pin can break the tip, especially in cold weather. Some people say this can’t happen, yet Mauser made millions of bolt rifles having a steel disc in the stock that made possible quick disassembly of the striker parts to replace the firing pin. The 1903 Springfield had the front 2 inches of the striker (firing pin) removable for quick replacement. There was a reason for this.

All the older pumps and autoloaders are subject to firing pin tip breakage if dry fired. All their mechanisms, however, prevent firing until they are closed and locked, so the only way to relieve mainspring pressure is snapping.