The only centerfire rifles that need snap caps are doubles. All the others are not harmed by dry firing them.
If you think snap caps protect your bolt action rifle's firing pins, measure the force on the cap's "primer" to push it in 1/16th inch. Then compare that to your rifle's 25- to 30-pound firing pin spring's force that smacks primers.
Go to a centerfire rifle match and watch all those people dry firing their bolt action and semiauto rifles without snap caps. Same thing at a centerfire pistol match with handguns. They do that thousands of times without issues. Took a friend to a match and he asked me after the first stage why all those people were dry firing their match rifles without snap caps. He had a hard time believing no damage was done and they did it all the time. And what about all that "snapping in" that military folks did with their M1903's, M1's, M14's and M16's without snap caps?
What's the difference in bolt action firing pin impact force against its stop in the bolt with rubber pencil erasers, silicone, hot glue, Delrin or rubber rod in the case's primer pocket or nothing at all? It's easy to measure. That firing pin's traveling about 80 mph or faster.
Here's a secret most folks don't think, or even know, about. Bolt action rifle's firing pins have little, if any force on them applied when dry firing. The cocking piece on the back end of the firing pin has a dimension that stops the firing pin from going forward against any stop in the bolt. The camed extension on the cocking piece doesn't touch the bolt at its tip when its full forward. The full force of the firing pin spring slams the flat front of the cocking piece against a mating flat inside the bolt sleeve. That's the part that takes the force of the firing pin's forward impact. Strip your bolt then push the firing pin into the bolt as far as it'll go; note how far its tip sticks out from the bolt face. Then compare that to what a fully assembled bold has the tip sticking out of the bolt face in its fired condition.
The firing pin itself is not slammed into anything except a primer, or whatever's in the pocket, in a loaded round. There's no stress whatsoever on bolt action firing pin tips with empty chambers. The stress is on the cocking piece and bolt sleeve that are made to withstand dry firing; there's more metal back there to withstand the impact. If snapping in really did hurt firing pins, there would be decades long stories of people snapping in their match rifles ruining firing pins; there are none. There's more force against a hammer head driving many thousands of 16d nails through hardwood. Does that hammer head wear away?
And floating firing pins in other firearms have little stress applied to them when the arm's dry fired on an empty chamber. The most stress it has on it is when it impacts a live primer in a case.
