I use already-fired .22 shell cases to "de-cock" my .22 guns. I just put a spent .22 shell casing in the gun chamber, then close it, then I pull the trigger. It de-cocks the gun without harming the firing pin. I leave the empty shell in the gun. (Warning: if the gun chamber is really oily inside, this will make it harder to open the slide/bolt, as the oily shell seems to "grab" the inside of the chamber).




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