FGMM 175’s too long?

[DustyElgin]

I recently picked up a .308 DMR from APF which I am very excited about. It’s a 1:10 twist and I e heard nothing but good things about FGMM 175 SMK’s as far as factory ammo goes, so I picked up a few boxes. At the range today I had a few failure to fire. I inspected the rounds that didn’t fire and noticed a ring on the bullets from being pushed into the rifling so the bolt wasn’t fully locking in. My question is, are these rounds just too long to use in my rifle or is the chamber out of spec?

 

[DocRDS]

What the OAL of the rounds? Not had any issues myself but of course that just makes you want hit me with a bat.

Grab some calipers and see if they measure 2.800. Then you can see if its you or the ammo.

 

[nn8734]

Take a round, paint the bullet and top portion (neck/shoulder) with a sharpie, chamber then extract it.

Post a photo of the painted round once extracted

Measure the CBTO. If it’s 2.160 or less it’s not likely it’s hitting the lands unless your throat is really short.

 

[celltech]

I have both 168/175gr FGMM and measured several rounds. All of them averaged around 2.211" BTO and 2.8" OAL. Have you tried any other ammo yet?

 

[bigjake83]

I recently picked up a .308 DMR from APF which I am very excited about. It’s a 1:10 twist and I e heard nothing but good things about FGMM 175 SMK’s as far as factory ammo goes, so I picked up a few boxes. At the range today I had a few failure to fire. I inspected the rounds that didn’t fire and noticed a ring on the bullets from being pushed into the rifling so the bolt wasn’t fully locking in. My question is, are these rounds just too long to use in my rifle or is the chamber out of spec?

I have seen those rings before, it just has a tight throat and those marks are from the reamer. Just shoot it and they will go away or you can CAREFULLY work it with JB.

As for not always chambering are you keeping the BCG Wet?

 

[KineticPerformance]

I've also seen big frame gassers have what appears to be a light strike or FTF unrelated to the chamber. I had it happening with three uppers on a single lower. When it happened in my gun it took a little bit to figure it out. It ended up being a buffer that didn't have enough slide-hammer effect so I was getting enough bolt bounce that I was getting light strikes even with an extra power buffer spring.

 

[buggz]

I've also seen big frame gassers have what appears to be a light strike or FTF unrelated to the chamber. I had it happening with three uppers on a single lower. When it happened in my gun it took a little bit to figure it out. It ended up being a buffer that didn't have enough slide-hammer effect so I was getting enough bolt bounce that I was getting light strikes even with an extra power buffer spring.

What was the resolution?
You changed to a stiffer buffer?

 

[KineticPerformance]

What was the resolution?
You changed to a stiffer buffer?

I ended up getting a different buffer after testing several from that company. Eventually they had me test an "industry standard" buffer and it fixed the problem. There was almost no room for movement of the weights inside the buffer they made.