I was working on a Stevens 311 16 gauge shotgun. I broke it down and installed a reduced power Wolff spring kit to make it a little easier to break open. When I got it back together, I discovered that the left firing pin was stuck out and refused to budge.

Figuring I did something wrong, I broke it back down and removed the left firing pin. I discovered that the firing pin spring had somehow gotten wrapped around the firing pin and become twisted out of shape.

I ordered a new firing pin spring and reinstalled the left pin. I tried operating it with a screwdriver but it became lodged in the pin hole and had to be tapped out. I removed the spring and found that I couldn't make the pin go through the hole without becoming stuck.

Thinking the pin was deformed, I swapped out the right firing pin and experienced the same problem. No problem was present on the right side.

I'm confused as to why this would happen, as the gun had gone through 50 shells without a misfire before breakdown. A physical inspection of the pins show them to be practically identical...

Is it a common problem for Stevens 311A's to have poorly cut firing pin holes? Is this a problem I caused or just something that has chosen now to surface? And how can I fix the problem?

Jeff
I Bought a M311A many years ago,and it always worked flawlessly.I did put a custom made(higher profile)safety on it.My Hunting Partner got tired of me complaining of missing Partridges.
Frank

Jeff, This is what I would do if me, I would take a set of calipers and take a reading on bought pins, they should be the same and i bet they are, write down you reading, go to a good hardware store, because you will most likely have to buy a number bit, with the reciever viced down level, and if you have a drill that has a level keep her level and drill that hole, you may just take that little burn out, drill slow. It doesn't take much of a bur on a small part like a firing pin hole to hang it up. On another forum, somewhere, I read that another person was having problems with a simalar problem. I like to take all my firing pins, and chuck them up in my Atlas 109 lathe that I have a drill chck on, chuck up the firing pin with the part of the pin that goes threw the reciever, put light oil on it, running it on low speed hit it with a little 1500 grit sand paper, and finish off with 2000 grit. When you were putting that back toghter if that pinwas hung out just a little tiny bit, the barrel may had kit it when closing, and placed a small bur.
I this help
Greg

The slightest amount of bend or run-out in the pins will cause them to hang-up too. If I read your post correctly, when you swapped the right with the left, the pin from the right hung-up as well.... I vote for a buggered up hole, could be nothing more than a little spot of rust or dirt. I don't like using a drill bit in holes, to risky to wallow it out and cause major damage. I use a diamond riffler file if the hole is big enough in diameter, in smaller holes use a file type torch tip cleaner. Occasionaly the rear of the receiver where the pin goes through will get peened off just enough to cause the pins to hang. If you order any more parts, get yourself at least two sets of spare firing pins and keep them around. It's not common but occasionally one will just snap off.