I have a P220 that the serial number indicates it was made around 2002. The slide is carbon steel with the separate breech block. Does this gun use the long (2.4675) or short (2.4345) firing pin? Thanks!

I believe there’s more difference between the two types of P220 firing pins than length, but the one in my spares that’s for the older pistol with carbon steel slide and removable breechblock is 2.440 inches long.

Thanks. I asked because mine measures 2.438 on my calipers and I have been getting some light primer strikes lately. I took the firing pin out and cleaned the channel with a dry Q-tip. Not much dirt came out but the channel felt rough inside. After reassembly still getting light hits, maybe once or twice per mag. The gun is a police trade in so I was thinking the pin is getting a bit worn? I have replaced the main spring with a new factory spring. Any ideas?

That’s puzzling. It seems unlikely that just wear would cause light strikes, especially as the length is virtually the same as the new one I measured (I actually got 2.438 the first time).

Depending upon how you cleaned the firing pin channel, perhaps there’s some stubborn hard lube/solvent buildup that you didn’t get out—? Also, have you cleaned the barrel chamber well, to ensure the cartridge is seating fully? (That seems unlikely to be the problem either, but ….)

And what ammunition are you having problems with? Did the light strike misfires just start?

The ammo was handloads but I have had zero issues with this ammo in any of my other .45's. I will try some factory ammo and see if that makes a difference. I will take the firing pin out again and see if I can do a better job of cleaning the channel. I hadn't shot the gun in almost a year but it functioned fine the last time I had it out.

Did you, or anyone, ever install a lighter mainspring?

Handloads are suspect.

^^

...or a heavier firing pin return spring?

If it has been dry fired a LOT the firing pin can sometimes have a raised edge where it contacts the roll pins/positioning pin.

Use a fine stone to remove the raised edge as it can drag in the firing pin channel.