Firing pin

Snav · Apr 13, 2018

I noticed a blackened firing pin indentation in one of 35 loads I fired in a new rifle. Upon examination with magnifier it seems that there is a small dimple in every primer as if the pin was turned on lathe and cutoff was not complete or no polishing/deburring. I took pics but the lack of 3D doesn't do it justice. Very obvious from MKI eyeballs that it is a incomplete cutoff..

So I can clean that up but is the firing pin hardened ordinarily or would polishing it with an Arkansas stone be ok?

Muleskinner · Apr 13, 2018

If the gun fires I wouldn't bother

Snav · Apr 13, 2018

So let the ocasional perforated primer do the smoothing?

Bob A · Apr 13, 2018

While I'm ignorant of the intricacies of gunsmithing, I suspect that cracks or irregularities in the business end of the pin would cause it eventually to succumb to stress, and cause the pin to fail. It might last longer with a bit of polishing, so long as it wasn't materially overshortened by the polishing.

Snav · Apr 13, 2018

So I guess the real question is there a hardened surface to be considered?

DutchV · Apr 13, 2018

What sort of gun are we talking about? I'd probably try to polish it out, but knowing that I might have to replace the pin if I goober it up or make the pin too short.

Snav · Apr 13, 2018

it's a 6.8 SPC BCG from Brownell's - M16 BCG 6.8MM SPC NITRIDE MP

Maybe I got a microstamping firing pin and just can't read the writing

GuitarmanNick · Apr 13, 2018

I would contact Brownell's and let them know that you need a new firing pin. It appears to have missed a couple of steps in it's manufacturing based on those pictures. Check the rest or that BCG for unusual marks, too.

Snav · Apr 13, 2018

So I remembered I had a spares kit from DPMS, dug it out and found a new firing pin in it. Removed BCG from rifle and got firing pin in question out, Damn! Now maybe thats the latest in oil grooves but compared to the DPMS it was an Orange to Nectarine difference. There is not a single smooth surface on the whole thing. I probably would never have noticed if the stud on the tip hadn't pierced a primer.

Brownell's is sending a new one.

GuitarmanNick · Apr 14, 2018

I bought a complete rifle package for my first AR build and had a similar issue with the firing pin. A poorly finished cam pin was tearing the firing pin up. Contacted the seller and the sent a new cam bolt and firing pin. I was able to clean up the original firing pin and cam bolt and they work fine now but will be used only in an emergency and kept as spares.

The problem was a rough edge on the cam bolt that was scoring the firing pin with each cycle.

DutchV · Apr 14, 2018

The tip should be polished smooth, even if the rest if sort of rough. Glad to hear they're taking care of it. Brownells is good about customer service.

outrider58 · Apr 14, 2018

You need to measure firing pin protrusion. That way you'll know whether or not A) a 'smoothing' of the pin will keep it within spec B)whether or not the pin IS within spec now.

I know what the specs are for 5.56/.223 and or 300 AAC, but I'm not sure if 6.8 carries the same spec. I would ask clandestine.

Firing pin

The #1 community for Gun Owners of the Northeast

Member Benefits:

Snav

Active Member

Attachments

Muleskinner

Ultimate Member

Snav

Active Member

Bob A

όυ φροντισ

Snav

Active Member

DutchV

Ultimate Member

Snav

Active Member

GuitarmanNick

Ultimate Member

Snav

Active Member

Attachments

GuitarmanNick

Ultimate Member

DutchV

Ultimate Member

outrider58

Eats Bacon Raw

Users who are viewing this thread

Latest posts

Forum statistics

Latest threads

Forum statistics

Share this page