Marlin 336 Firing Pin Repair

[gzig5]

I'm not sure how it happened but I managed to break the tip off the firing pin on my 1955 336 RC in 35 Rem. Replacement pins are available, but they aren't free and I like to fix stuff I break. Didn't think to take pictures unfortunately but if you look at a 336 firing pin I think you'll get the picture. The pin broke right where the radius starts from the pin tip back into the body. The plan was to drill it out and fit a new pin section to the original body. I chucked it in the lathe and with it spinning carefully squared/dressed the broken end. I then started the new hole with a 90 degree spot drill, just starting the hole and making sure it was centered and didn't wander off. The spot drill works better for this in my opinion than a 60 degree center drill. The part that broke off disappeared but I selected a drill bit a few thousandths smaller than the hole in the bolt and proceeded to peck drill almost 3/8" deep. That seemed like good depth to give plenty of support. The FP body drilled surprisingly well. I was concerned it was going to be hard, but the middle definitely was not. I was going to use a piece of music wire for the tip but I didn't like how loose it was in the drilled hole so I estimated what I needed for length and then cut the drill bit I'd used off on the shank end. The drill bit is about the right hardness and it fit just right in the hole. It was set up vertical in the vise and glued in place using Loctite 680. I wanted to silver solder it but was nervous about the heat required and in the end I couldn't find my flux anyway. I'm confident that pin will stay in place for a while. Gave the glue a day to cure then chucked the FP in the lathe and running at 1000rpm I used stones and crocus cloth to put a nice hemisphere on the tip. I finished with 1000 grit and I have .064" protrusion from the bolt face. Put a primed case, no powder/bullet in the chamber and dropped the hammer. Nice bang and you can't tell the appearance of that primer from the ones before the pin broke. Looks like job done. Hope this helps anyone who runs into a similar situation. I used similar method to convert my 1881 Vetterli to centerfire years ago.

[44man]

Many years ago I fixed them the same way but if I remember I soft soldered them in.
Marlin pins are prone to break and a brand new one came in with a broken pin done with one dry fire. It is one gun never to be dry fired. Now with the safety, you can do it to work triggers.

[izzyjoe]

An old gunsmith told me he made new ones from old Philips screwdrivers cause they are the proper diameter and you get plenty of length to make a one piece, and get away from the two piece design. I see now that they sell the one piece for cowboy action shooters. Truth be known I've never broken one, but I keep a spare handy!

[bstone5]

I make small replacement firing pins out of Grade Bolts, turn down the bolt in my lathe, have made several for break open shotguns. All have work without any failures.

[44man]

There is a special steel my gunsmith friend uses but I forgot the designation.

[wrench man]

There is a special steel my gunsmith friend uses but I forgot the designation.
Probably "Drill Rod"?
I've only broken one Marlin firing pin, it was the rear pin on my '09 1894 25-20, I was given a modern day pin for free, so it went back box stock, no issues since.

[44man]

Probably "Drill Rod"?
I've only broken one Marlin firing pin, it was the rear pin on my '09 1894 25-20, I was given a modern day pin for free, so it went back box stock, no issues since.
Not drill rod. It had a steel alloy designation he told me would never break.

[HangFireW8]

Call Brownell's. You'll get a recommendation for either an oil hardening or water hardening steel rod. Follow the tempering instructions carefully for that type of steel, in particular don't overheat the tip.

-HF

[John 242]

I was going to use a piece of music wire for the tip but I didn't like how loose it was in the drilled hole so I estimated what I needed for length and then cut the drill bit I'd used off on the shank end. The drill bit is about the right hardness and it fit just right in the hole.

A buddy of mine say's he has used RCBS decapping pins before and highly recommends them.