[Dixie Gunsmithing]

polyphemus,

The barrel and slide are locked together during the first amount of slide recoil, and it's not much, about 1/4" or so, until the lugs start to disengage from the slide. This happens after the link swings up, actually digging the lugs into the slide frame, and then they start to drop again, as the link passes center. The recoil spring, though, isn't compressed much, yet, and it's tension isn't that much. However, the bullet leaves the barrel, lickity split, and the barrel and slide stay locked together while this happens, so the spring can control this time, but minutely. In other words, it can keep the slide stationary just a few milliseconds longer, than it would without a spring, as the spring pressure would effect the mass of the slide during inertia on recoil. This, especially, since the spring is under pre-load from the barrel busing, already compressing it some, when it is in place. In other words, the spring is not completely uncompressed when the gun is at rest, and is supplying an opposing force to the slide.

The idea of a heavier firing pin spring, to a lot, is to keep the mass of the firing pin from to wanting to travel forward, due to inertia, than with a weaker spring, over a heavier recoil, forward and return, (but the factory spring is purely a safety measure to keep the firing pin away from the primer, when returning to battery, or dropped, and the recoil inertia could only send it against a fired primer). The problem is, though, that when the hammer strikes the firing pin, with the force put to it by the hammer spring, is if it has enough force to indent all primers fed to it, as the weaker spring would allow. The hammer imparts movement against the firing pins mass, creating inertia at the firing pin, and then the pin compresses its spring. The heavier the spring, the less power forward.