Haven’t seen it discussed yet and they are some pretty big changes, which I’m guessing are to address the pierced primer issues with 6.5 Creedmoor.

Firing pin tip O.D. new on the left.


Firing pin travel limit change for shorter bolt. Grooves at the base of the firing pin.


Smaller diameter firing pin hole. Both bolts are new, but the newest one (on the left) has definitely been test fired.


New bolt is about 1/8” shorter.


Extractor pin is retained with a roll pin. New bolt on top.


Interesting that it’s actually retained.


Both new bolts are MPI stamped, my original is not, and the new one is stamped HP. I’m assuming for high pressure tested.


They are not interchangeable, they only work as a set.

I have both 308 and 6.5 barrels, once I get some free time and it stops snowing I will get to the range for testing. I’ve put several hundred rounds of 6.5 through my rifle and I haven’t had any pierced primers, but they are pretty close with hot hand loads.

Interesting. I think that is the fix a lot of people were proposing when the 6.5 issues started popping up.

Did you ever shoot factory ammo out of your 6.5 barrel?

A few boxes of Hornady 140gr.  ELD-M and 140gr. HPBT from Magtech.

Good to know. I have a theory about most of the pierced primers coming from factory ammo loaded with bolt guns in mind. Most of the people shooting hand loads or the Hornady stuff seem to be unaffected.

It looks like the new bolt firing pin combo will be a good fix.  

Hopefully this will spur FN into producing more barrel assemblies. The dried up pretty fast, especially the 6.5s.

When I sent my 20S CM in for popping primers, they sent it back with new FP and bolt. Seems to have corrected the issue. Ammo exhibiting the issue was Nossler 140gr.