Changing 870 firing pin

You are on target. That pin can be a real bear to drive out with a hammer and punch. I suspect a press would be the way to go. I have only done this once. My '55 WM came with a broken firing pin. It was really tough to get that retaining pin to move.
Mike

The answer to any gunsmithing question is always "use a bigger hammer."

Put the bolt on a good bench block, FLAT side down, and with the rear hanging over the end of the block so as to allow the pin to move out.

Use a 1/8" punch to drive the pin out. If it's resistant, cut a punch off to about 1/2" to 3/4" to make a "Starter" punch. The shorter length prevents the punch from flexing or bending.

With the pin out, the firing pin and spring is released, and the locking block can be removed out the bottom.

NOTE: The firing pin retaining pin has an end that has retention grooves in it.
Make sure when replacing the pin that the SMOOTH end goes in first.
The grooved end serves to lock the pin in place.

The answer to any gunsmithing question is always "use a bigger hammer."

Click to expand...

Yep never force it get a bigger hammer!!

Change the return spring also. If you use a titanium pin to replace it most likely it will never break again.

I have broken 870 pins after about 100,000 rounds at trap usually they break in the VERY cold weather. Never broke the titanium pin.

Use penetrating oil if its too hard.

Holy old-thread batman!

It's also important to point out that a person should be sure they are punching on the SMALL end of the retaining pin to remove it. Also be sure that your punch is no bigger in diameter than, and perhaps smaller in diameter than the small end of the retaining pin.

As Gezzer said, it's a good idea to replace the return spring too if the gun has shot a lot of rounds.