In my modest collection of S&W revolvers I have a pretty equal number with frame mounted and hammer mounted firing pins. Looking with a magnifying glass, I'm certain that the hammer mounted pins stick out more.

I've never had either type fail to fire. My 642 seems to stick out the least and the tip has a cone shape rather than rounded but it always works too. The fired primers all look like they are being struck about the same no matter the type of firing pin.

As far as inertial firing goes, I can't imagine a scene where that could even be a remote possibility.

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Ron
NRA Life Member