Dealing with a frozen firing pin spring on an old shotgun

I was cleaning my granddad's old side by side last week and the firing pin spring was totally seized up. Nothing I tried at first would get it to budge, not even penetrating oil. I ended up soaking the whole assembly in a mix of acetone and transmission fluid overnight, which I read about online. The next day, I used a small punch and light taps to work the spring loose bit by bit. It came free without any damage, which was a huge relief. Cleaning off the gunk showed it was just years of built up grime and a little surface rust. This method saved me from having to order a new part or force something and break it. Now I tell folks to try a long soak with that mix for really stuck small parts before going harder on them.

3 comments

3 Comments

noahc141mo ago

My uncle's 12-gauge had a frozen spring last year. Tbh, that acetone and transmission fluid soak is genius. Glad it worked out for you.

the_riley1mo ago

Used some penetrating oil on mine and it freed up, maybe it's just me.

wade8141mo ago

What brand of penetrating oil did you end up using, @the_riley? I've heard some work better on old rusted stuff. That acetone and transmission fluid mix noahc14 talked about seems like a tough fix for frozen springs. Did the oil loosen things up fast or did you wait a bit? I wonder if certain types cut through gunk quicker.