M8 Broken Firing Pin

Information on Malfunctions and Care of your Model 8 & 81
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Wildgoose
Posts: 235
Joined: Sat Nov 06, 2010 5:53 am
Location: Nebraska

M8 Broken Firing Pin

Post by Wildgoose »

Working on cleaning up the insides on a Model 8 just purchased. Found the original firing pin broken at the tip. Must have been that way for a while looking at the peening on the edges. I pretty sure I have read here in the past one can install the newer replacement pin and spring set up. Just looking for some confirmation on this. I have an original on order too just in case but would like to go with the spring loaded set up if possible.
Thanks

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S and S HUNTCLUB
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Joined: Fri Nov 23, 2012 2:59 pm

Re: M8 Broken Firing Pin

Post by S and S HUNTCLUB »

Wildgoose, That will work just fine, as the bolt carrier and bolts are the same on the model 8's and model 81's. However, I have noticed in the past that firing pin lengths will vary. Therefore, once the new firing pin and firing pin spring are installed, "push in" the bolt carrier latch spring and rotate the bolt into the bolt carrier, to check that you have enough of the tip of the firing pin protruding through the face of the bolt to make contact with the cartridge primer.

One a side note: There's a ton of rotational torque on the bolt carrier assembly components, when the rifle is fired. When you have your bolt disassembled, you'll need to check for burrs in the cam pin locations on the bolt carrier, as well as burrs on the cam pins and burrs in the elongated cam pin slots on the bolt. I have found that "Sticky Cam Pins" are the main cause for firing pins breaking.

When I disassemble a bolt carrier group, I have a small set of various jewelers files that I use to remove the burrs on the cam pins and the locations I just mentioned above. I use some honing oil and some 220-400 grit sand paper in sequence, to make sure that the surface of the cam pins are ultra smooth, before re-assembling the bolt carrier group. I also check the rear of the bolt carrier for damaged caused by the hammer. Sometimes, you'll find a burr on the back of the bolt carrier, that will effect the forward travel of the firing pin. Another thing to check is the outer surface of the bolt, making sure to de-burr it as well.

Once that is complete and all of the bolt carrier group parts are completely cleaned, I re-assemble the bolt carrier group with a light coat of Remington Rem-Oil. Once assembled, the bolt carrier group should rotate smooth as silk and that will reduce the chance of future firing pin breakage.

Enjoy Life, Bob @ S and S HUNTCLUB

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Phyrbird
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Joined: Mon Jan 07, 2013 10:53 pm

Re: M8 Broken Firing Pin

Post by Phyrbird »

Bob,
A very nice tip, KUDOS :geek:
Phyrbird
SOKY

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Wildgoose
Posts: 235
Joined: Sat Nov 06, 2010 5:53 am
Location: Nebraska

Re: M8 Broken Firing Pin

Post by Wildgoose »

Many thanks Bob. Just what I was looking for and I will indeed hit all those points. :D

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Wildgoose
Posts: 235
Joined: Sat Nov 06, 2010 5:53 am
Location: Nebraska

Re: M8 Broken Firing Pin

Post by Wildgoose »

Got the replacement pin in and all is back in order now. Did have a interesting thing happen I thought I would pass along. I ordered both the listed "original" pin and the listed "replacement " pin from Gun Parts Corp. When I tried the replacement pin the tip was too large to pass through the hole in the bolt face. The original pin how ever had a smaller diameter tip and did fit. So I wound up using the original pin and the spring combination. Out of curiosity I tried the replacement tip in several of my other rifles and found it to be too large for all but one of them. An M8 in 35Remington. So I guess if you order replacement firing pins for your rifles there is a chance that there will be a bit of a problem with the tip diameter depending on the gun involved. I could have opened up the bolt face firing pin hole if I had to but I am not big on modifying parts unless I have to. At any rate not a big deal but I thought the group my like to be aware of the variation that could exist.

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