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Well, another day at the range with what I thought was a fairly short mil-spec firing pin didn't go well. Hardened Arms shipped my upper with the short bolt and my mil-spec pins are piercing and doubling
I don't really want to lay out the money for a new bolt as there is nothing wrong with the one I have (other then being short). Does anyone know of a source for short pins that will work in the short bolt? I'm reluctant to start filing away at the tip of my existing pins as I'm not sure I can maintain a smooth enough surface to avoid problems down the line. Thanks!
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check with toolcraft
i would wager that is their design.
they have changes it
or get a group buy bolt
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Odin Works used that combination for long while, don't know if they still do.
My recent Toolcraft, measured out good.
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A5BLASTER Wrote:Get a group buy bolt.
makes better sense. Just got it done, thanks!
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11-28-2019, 03:30 PM
(This post was last modified: 11-28-2019, 03:49 PM by VASCAR2.)
You can buy a stainless steel firing pin and just shorten it till your within spec., approximately .01”.
Here is a link for an AR-15 SS firing pin.
https://www.midwayusa.com/product/1003337891?pid=584490
With a stainless steel firing pin you won’t have to worry about grinding through chrome plating on a carbon steel firing pin.
With a bolt length of 2.810” and a firing pin length of 3.2790” there is a .008” tolerance for firing pin protrusion. The longest pin I ever measured was 3.280” and most FP pins tend to be shorter than 3.279”. I haven’t seen a FP with a length as short for a .008” length (3.2790”-.008=3.2710”
. Everything I read indicates the spec length of 3.2790” with a maximum -.008” tolerance. Most other AR-15 parts are +or- .001”, just not firing pins.
If you add 2.810” + 3.2790” = 6.089”. If your combined length is no higher than this number and with .008” your Firing Pin protrusion should be with in spec with 2.810” bolt.
With a 2.800” bolt and a firing pin length of 3.269” (2.800”+3.2690”=6.069) if your combined length is less than .008” of 6.069” you should be within spec of .028” minimum and maximum .036” FP protrusion.
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When did you get your Hardened Arms? I thought they went out of business. I got a 16" 5.56 upper and an 18" Grendel upper from them abot a year ago. Really like them and wish they were still around.
I thought about selling my weapons back to the government, but after a thorough background check it was determined that the buyer has a long history of violence and is mentally unstable. Therefore could not pass NICS.
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I got my 18" Grendel upper from them just about a year ago as well. So far I like it but I'm still trying to find a load it really likes. The firing pin issue make be a contributing factor to unreliable results.. I have a group buy bolt on the way so I've got my fingers crossed.
