Ruger had one of their single six 22 revolvers in a little machine that cocked and dry fired it about once a minute when the first came out, ran 24 hours a day for weeks with absolutely no damage to the revolver.

If a 22 rimfire firing pin hits the chamber it is because the design is faulty or someone fit a fireing pin up too long. Should you ding a chamber it is an easy fix.

I could care less what you do, but for me if I want to master a firearm a lot of dry fire is mandatory. I feel that to build a target pistol that cannot be dry fired means it will not be in the winners circle very often. Having many Smith & Wesson hand guns in 22 rim fire I believe they are aware of this fact. There may be some who are naturally better shots than I am and may not benefit from dry-firing as much as I do.

Using snap caps on a semi auto means that every time you cycle the action you have to pick up the snap cap from the floor.