Firing Pin

[Steve_evetS]

I measured the protrusion of my firing pin. 0.042" anyone else have to modify the protrusion of their firing pin? I attached my pin to a Jacobs chuck drill and made sure it was centered, then proceeded to us a mini-file to remove material till it was 0.036" the maximum measurement for ar15/m16. Thoughts?

[Old Bob]

You may have had an "Enhanced" firing pin for 7.62x39 type 1 AR bolts. The enhanced firing pin has a longer tip than regular AR firing pins. They're made that way to improve primer strikes on steel cased 7.62x39 ammo fired in AR type rifles. The enhanced pin is on the left.

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[Steve_evetS]

You may have had an "Enhanced" firing pin for 7.62x39 type 1 AR bolts. The enhanced firing pin has a longer tip than regular AR firing pins. They're made that way to improve primer strikes on steel cased 7.62x39 ammo fired in AR type rifles. The enhanced pin is on the left.

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Thanks old bob what should I use to polish the end 2000 grit? Do u think it not being polished will end up in pierced primers? Should I just SEND IT! and see what happens?

[Old Bob]

Emery cloth or some of that red polishing compound on a cloth wheel.

[Steve_evetS]

Emery cloth or some of that red polishing compound on a cloth wheel.

I ended up just touching it up with 600grit followed by 1000grit. looks great cant feel any scratches let alone see any. Remeasured its at 0.345"I figured I keep it longer rather than shorter for the firing pin was on the long side and worked fine.

[VASCAR2]

Odin Works, Brownell’s and some early Toolcraft bolts were shorter than 6.5 Grendel bolts. A standard AR-15 223/5.56 bolt measure 2.800” +or - tolerance of .002”. When AA used a bolt face depth of .136” he lengthened the 6.5 Grendel bolt to 2.810”. An AR-15 5.56/223 bolt face depth of .125”. The Odin Works and Brownell’s 6.5 Grendel need a shorter firing pin. A mil spec firing pin measures 3.279” -.009” tolerance.

This all came to light when Odin Works barrels and BCG started getting pierced primers in 6.5 Grendel.

[Steve_evetS]

You may have had an "Enhanced" firing pin for 7.62x39 type 1 AR bolts. The enhanced firing pin has a longer tip than regular AR firing pins. They're made that way to improve primer strikes on steel cased 7.62x39 ammo fired in AR type rifles. The enhanced pin is on the left.

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Hey Old Bob,
Have U used the type I 7.62x39 pin? I think I need to order another for, the pin that I shaved is now causing a failure to fire situation do to light primer strikes.

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[Old Bob]

Hey Old Bob,
Have U used the type I 7.62x39 pin? I think I need to order another for, the pin that I shaved is now causing a failure to fire situation do to light primer strikes.

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Does the firing pin you modified reliably set off primers in brass cases? The pic shows a pretty weak strike on the steel cases. I take it, those examples did not fire. I think you'd be OK with a new mil-spec pin, but if not, you can try the enhanced pin. I got the enhanced 7.62x39 firing pin to use in my 6mm ARC AR in case I had light strikes on 220 Russian brass that has been resized to 6mm ARC. The headspace on 220 Russian brass is shorter than the headspace on 6mm ARC brass. To compensate for the different headspace lengths, I seated the bullets out to where they just touch the lands in the chamber throat & the case base is up against the face of the bolt. This will enable me to fire-form the 220 Russian cases to the 6mm ARC chamber. I hope the primers will ignite reliably with a mil-spec pin, but if they don't, I'll put in the enhanced 7.62x39 pin.

[Steve_evetS]

Yes Bob,
Brass cased primers have no problems igniting. The only problem I have is with the wolf steel cased primers

[Steve_evetS]

I reached out to Faxon and the REP said he had a few firing pins laying around and he said he might be able to send me one if he has that cartridge pin on hand.

[Growler]

Hey Old Bob,
Have U used the type I 7.62x39 pin? I think I need to order another for, the pin that I shaved is now causing a failure to fire situation do to light primer strikes.

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If you have light primer strikes, barring headspace issues, your first check should be your hammer spring. Triggers that use lighter springs to reduce break force are trading reliability and safety for “performance”. You can (mostly) have your cake and eat it too with full power springs, provided your trigger is a good fit for your requirements.

[Steve_evetS]

If you have light primer strikes, barring headspace issues, your first check should be your hammer spring. Triggers that use lighter springs to reduce break force are trading reliability and safety for “performance”. You can (mostly) have your cake and eat it too with full power springs, provided your trigger is a good fit for your requirements.

Thx I got a Rise Armament 434HP drop in and it worked great before I shave the firing pin down to .0345" from .042" it does fire brass just fine noooo problems but, the steel cased ammo I will get good primer strikes but, no fire condition. I am pretty sure it is because of the harder primers of the Wolf Ammo. I shaved it down because the Wolf ammo was experiencing ruptured cases and the pin protrusion should werk @ .0345" I guess you have to live and learn. shoulda kept it @ .042"

[VASCAR2]

It is very common to find split Wolf steel cases after firing. I have one 6.5 Grendel AR-15 that has a little larger chamber and Wolf Military Classic steel cases will crack/rupture more often in that rifle. I’ve never seen any evidence of damage from these cracked steel cases. This particular 6.5 Grendel was over gassed with some ammo but ran the Wolf 100 grain FMJ fine. I suspected the split Wolf steel case occurred when the body of the case hit the case deflector while still hot. I never tried to get any slow motion video to verify this. The split cases could be the result of poor quality Russian steel cases.


I have been around numerous AR-15’s in 6.5 Grendel and have never gotten a Wolf steel cased 100 grain FMJ which failed to fire on the first hammer strike. I never had any issues with Wolf/PPU brass cased ammo other than the brass having inconsistent quality for reloading.

[Steve_evetS]

It is very common to find split Wolf steel cases after firing. I have one 6.5 Grendel AR-15 that has a little larger chamber and Wolf Military Classic steel cases will crack/rupture more often in that rifle. I’ve never seen any evidence of damage from these cracked steel cases. This particular 6.5 Grendel was over gassed with some ammo but ran the Wolf 100 grain FMJ fine. I suspected the split Wolf steel case occurred when the body of the case hit the case deflector while still hot. I never tried to get any slow motion video to verify this. The split cases could be the result of poor quality Russian steel cases.


I have been around numerous AR-15’s in 6.5 Grendel and have never gotten a Wolf steel cased 100 grain FMJ which failed to fire on the first hammer strike. I never had any issues with Wolf/PPU brass cased ammo other than the brass having inconsistent quality for reloading.

Did u check out Mag Mods post? I am pretty shure my ruptured cases were from the magazine putting a dent gouge in the shoulder area for, that's were it was rupturing when I ran the wolf ammo last time out I didnt get any rultured cases just a no fire condition

[Steve_evetS]

I think they are sending it....
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