You should never dry fire your gun. Always put a round in the chamber before firing. It's better to repair holes in your walls than run the risk of damaging one of your guns...

Some .22s, and older guns in general aren't entirely good to dry fire. The 22s can peen the firing pin over and have issues, and in general older guns have worse metal, so the resonance can cause the firing pin to have fractures that'll cause it to break. Not an absolute rule, and a bit usually won't hurt, but in general unless its something easily replaceable its not a good idea. And cz75 pattern pistols can have issues with the firing pin block retaining roll pin getting bent out of shape, but thats more of an issue with design then dry firing, a snap cap or a heavier roll pin fixes the issue

That's why I like my guns like I like my economic theory, Austrian. I drive a Glock for the simple fact that it is retard proof, no safety to disengage, no decocking, and suitable to dryfire until my toes bleed.