I know it seems like a dumb question.  But I'm trying to understand the WHY part.  If you had a worn firing pin spring

what would be the malfunction?  Is it a safety issue?  

 

At what point should you replace it?  And are they all created equal?

just a shot in the dark, but I'm assuming it so you do not rupture the primer.

usually replace it with your return spring, if it is weak the pin will not get out of the way soon enough and it could break, you will get a drag mark on your primer when it gets weak enough.

Weak FP/Striker spring would result in light primer hits and malfunctions.

 

Springs wear by cycling (a cycle being a compression and a relaxation), your firing pin spring is cycled as much as your recoil spring. As such I generally replace them together (roughly 5k rounds or 1 time a year on my Glocks)

 

Flowing the PM schedule for your particular firearm will typically keep you from ever experiencing malfunctions relating to parts failing.

I recently bought a new recoil spring for my Spartan 9mm and it came with a new firing pin spring. There was no mention of why but it did say to replace it when replacing the recoil spring. I figured they knew better than me so I did it. The spartan ran great with the new recoil spring 9#'s but I don't know what the firing pin spring did...

I can't think of the last time I replaced a firing pin spring.  The only time I ever had a firing pin related malfunction was primer flow using magtech primers.

I figured it needed to be done so I replaced it and yes the STI Spartan is a 1911 9mm. Since I did some work on it the pistol has been great. It makes for a great gun for steel. Since I got it working so good I have even thought about selling my CZ75 which I said I would never sell, I probably won't but It crossed my mind. I would now love to have an STI Edge or Executive but the aren't cheap

I know it seems like a dumb question.  But I'm trying to understand the WHY part.  If you had a worn firing pin spring

what would be the malfunction?  Is it a safety issue?  

 

At what point should you replace it?  And are they all created equal?

 All these learned answers....

 

What type of pistol?