How Does the P7M8 Firing Pin Block (Drop Safety) Work?
I have come to the point where I want to make sure I entirely understand how the P7M8 operates, soup-to-nuts, as I will be carrying it. I aught to know how the thing works if I'm trusting my life to it; I aught to understand how it keeps things from going wrong and what things can happen to force something to go wrong. Moreover, I'm in a technical field, and I'd look like an idiot if someone asked me something simple about how the gun I carry works and I didn't know the answer :biggrin:. I have spent a good deal of time reading up on the action and examining/toying with my pistol disassembled to think about what each part does. I have learned a great deal, but there is one thing I can't quite figure out: the drop safety.
As I understand it, the primary thing keeping the gun from going off when you decock it is the sear. Even when all the way forward, the sear holds the firing pin back enough so that it can't move out of its hole and engage a primer. The secondary firing pin spring holds it back this same amount at rest, but that spring could be overcome were the sear not also in the way, as it is when firing. The trigger can only disengage the sear all the way at the back (when you want it to), so the sear spring ensures that the sear will be engaged when it is at the front (decocked). In theory, you could imagine thinning the sear down a hair, perhaps from being slammed forward from decocking a lot, and if I understand everything correctly this would (in the absence of the drop safety) make the gun fire whenever you decock it, basically turning the P7 into a hand grenade with no pin. However, thankfully there is an extra thing keeping the firing pin from hitting the primer: the drop safety! At first I thought that the drop safety just introduced extra spring tension on the sear when it was cocked, but I realized that this was silly and would make the safety functionless at any time when the sear was not cocked up to it.
So, how does the firing pin block/drop safety work? I realize there is two designs. I am most interested in the new one, but would also like to know how the old one works for comparison.