Install Titanium Firing Pin
Replacing the firing pin is an easy task and requires the following tools:
1) Your breech block assembly
2) A 1/16 steel or brass punch
3) Hammer or mallet
Step 1: Remove Breech Block
Disassemble your SPAS 12 and remove the breech block. You won't need the operating handle so you can set it aside.
Locate the firing pin retaining pin towards the rear of the breech block, pictured to the right.
Begin punching the firing pin retaining pin out of the breech block. BE CAREFUL. This is a rolled-steel pin and the last thing you want to do is mushroom it out or damage it. If it doesn't come out easily you should take it to a competent gunsmith to avoid damaging your shotgun.
The retaining pin does not need to be fully removed, however since the firing pin is spring-loaded you will want
to keep it covered so it doesn't shoot across the room. The picture to the left (click to enlarge) shows all the further the pin needs removed to release the firing pin, slowly remove the punch and remove the firing pin.
You'll be left with a pile of parts that look like the picture to the right.
Now is a good time to clean and re-lubricate everything. I usually coat everything with a thin layer of Frog Lube. If you don't have Frog Lube available, lubricate the sliding surfaces of the locking block, and perhaps a light coat on the firing pin spring.
Remove the firing pin spring from the old firing pin and swap in your new one.
Step 2: Remove Firing Pin
A worn or damaged firing pin can cause malfunctions like light primer strikes, not firing at all, or your firing pin can even snap. The following guide will instruct you on how to replace it, or if you're not the reading type, watch the video here!
Replacement upgraded firing pins are now available through the SPAS 12 Project to remedy these issues, check them out here.
Step 3: Reassemble
Start by replacing the locking block of your breech block, this is easiest to do front-first.
After that you'll slide your new firing pin and spring into the breech block. Make sure the flat spot on the rear face of your firing pin s facing upward so the retaining pin can slide over it, keeping it in place.
Notice the flat face of the firing pin is facing upwards!
Once you have the firing pin aligned correctly, you simply hammer the retaining pin back in to place and enjoy your new upgraded firing pin.