I look at snap caps as cheap insurance. Why beat up the firing pin and internals when you can get a set of snap caps for less than $30 in most cases. No different than not letting the slide slam closed on a semi-auto with the slide release when there is no magazine. It just beats up the internals. Can it be done ? Sure. Will it damage anything ? Not occasionally. But do it enough and you're putting undue wear on things that are easily avoided.

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