Lately I've taken note of the availability of aftermarket extended firing pins, especially for pistols. The fp's seem to be associated with custom builds designed to make the pistol (CZ 75B for the sake of discussion) operate more like a finely tuned competition or even bullseye units.
True, manufacturers tend to install stiff hammer springs to make the gun "safer", in other words more difficult to fire. Kind of like the child proof lids on prescription drug containers. What could be safer than a gun that won't fire? Admittedly most off the shelf pistols can work very well with lower power hammer springs. To a point. However, you can't change just one thing on a firearm without affecting 1 or more other things. Random changes can cause unpredictable results especially when you change a bunch of things at the same time. But let's stick to the hammer and the mainspring.
The whole point of the pistol is to ignite the ammunition primer reliably. There is no formula that will let you predict what to do to obtain reliable ignition. Too many variables. Even the manufacturer has to get this information experimentally (or empirically if you are a snob). The primers obviously require a certain combination of force, speed, penetration, etc. Consider that you can take any primer and crush it very slowly in a vice until it is flat. That primer will not go off. You have completely flattened the primer without ignition taking place. The vice must be at fault, right? Nope.
To ignite a primer we have to have enough force delivered at enough speed to make a primer go off. So how does all this apply to installing a longer firing pin? We maybe lightened up the hammer by removing metal to achieve faster lock time. How did this metal removal affect the primer ignition? We don't really know until we experiment. The hammer will move faster, but will that increase in speed buy you anything at the tip of the firing pin? The firing pin has mass, and must still be accelerated at a rate that will ignite the primer. But getting the firing pin moving will be more difficult with the lighter hammer and lighter hammer spring. Nothing is obvious or simple about this relationship. The logic of installing a long firing pin escapes me. It does not matter how long it is if the pin is not traveling fast enough to fire the primer. This is not a firing pin protrusion issue.
Consider also for a moment that most modern self-defense guns have inertial firing pins to avoid slam fires and safety related malfunctions. We do not have an easy way to calculate how far the pin must go to achieve ignition. But note that since the design is inertial, that pin CAN extend plenty far enough if it is given enough force to fly forward. And, as an inertial design the hammer imparts a certain momentum to the f.p. and will NOT be in contact with firing pin at the end of the firing pin's travel. So what is the firing pin protrusion measurement? I can't think of a simple way to know that, especially since reliable ignition is dependent on so many things. I really don't see how making a longer pin will contribute to anything at all unless the point is to turn the system into a non-inertial design. And finally it escapes logic to see how installing a weaker firing pin return spring will make a pistol smoother and more reliable and more likely to achieve reliable ignition. You need a certain weight firing pin spring for safety reasons but also to help get that pin out of the way once the primer has ignited. If the pin is still hanging out, ejection may also be affected. Everything affects something else. Piercing primers isn't an example of fine gun tuning. So what's the point? Are we talking faster lock time? Remember this is a self-defense gun.
Those are just a few thoughts that cross my mind on this extended firing pin topic. One final observation is that there are so many posts claiming "light strikes". Photos show a few lightly dented primers that did not go off, and other fired brass that did go off. Folks, pictures like this do not prove anything. Fired brass will show a much bigger dent but that is simply because the round fired. The case is blown backwards against the recoil shield. The firing pin is still hanging out of the firing pin port. There are other reasons why some ammo fires and other ammo does not. Once lots of new parts and lighter springs have been installed, many times all at once, it is not easy to say what is happening. As one engineer said, "It isn't that simple". Well, it isn't.
OneWay
