M1A 6.5 not chambering ammo

[Deplorable77]

I have a National Match M1A chambered in 6.5 creedmoor. Saturday I fired 240 rounds of 140gr American Gunner ammo through it with zero issues. Today, same ammo, same mags, and the bolt will not fully close and the rounds are getting stuck in the chamber. Have to hammer the bolt open and the bullets look like they have "pull marks" about a 1/4" above the brass, same thing is happening with Hornaday 129sst. . I put these same "stuck" rounds in a Winchester M70 and it feeds, cycles, fires just fine.
Back to the M1A, I load the same mag with S&B ammo and it chambers and shoots just fine. Any thoughts?

Adding: I just tried it again so I could add a picture and the case came out but the bullet is stuck in the barrel......

 

[Deplorable77]

Tapped out with a cleaning rod

 

[Spoonbill]

Maybe a bad box and the bullet is wide enough for a tight chamber? Thats pretty strange though. If you have some calipers measure the bullet and see if its bigger than the other ammo. Just speculating but there could be carbon build up in the chamber. Have you cleaned the rifle since the last time you shot it.

 

[Lawnboi]

New lot of ammo?

Looks like they are into the rifling

 

[Deplorable77]

I was wondering that also, but I've never known this platform to stop operating unless it was a mechanical failure. ... but I gave it a thorough scrubbing a few hours ago. Loaded 8 more mags (1 American Gunner) the other 7 were all different factory offerings. Everything cycled except the AG. Its gotta be a bad lot of ammo, but I don't understand why it jams in the M1A, but fires fine through two different bolt guns. Another pic of the last try.

Maybe a bad box and the bullet is wide enough for a tight chamber? Thats pretty strange though. If you have some calipers measure the bullet and see if its bigger than the other ammo. Just speculating but there could be carbon build up in the chamber. Have you cleaned the rifle since the last time you shot it.

 

[Deplorable77]

Different lot than Saturday, yes. I'm leaning towards a bad lot

New lot of ammo?

Looks like they are into the rifling

 

[Lawnboi]

Your bolt guns might have longer throats. That and the calming of the bolt likely has the torque to push the bullet into the rifling.

 

[Deplorable77]

.2635 dia on everything else except the AG. Its .264

 

[Deplorable77]

5 random bullets pulled from a box OAL ::
AG
2.8060
2.8070
2.8075
2.8090
2.8125

Barnes vortex 127 lrx
2.7525
2.7525
2.7535
2.755
2.757

S&B Tactical 140 fmj
2.739
2.7395
2.7395
2.7405
2.7415

 

[Deplorable77]

Definitely a bad lot of AG. I opened 12 boxes of 147 ELDM, took two rounds out of each box, loaded them into one mag and they all cycled just fine.

 

[mt100gr.]

Interesting. I have some AG on the shelf, just out of curiosity, what's the bad lot #?

Good news is that it sounds like you're well stocked with 6.5CM ammo!!

 

[Deplorable77]

I'm down to ~1500 rounds in factory 6.5 offerings and have all components to load about 3x that amount...
What sucks is that I'm leaving for TX tomorrow and I re zeroed my thermal on Sat to the AG load and burned my open case of AG. (without saving the old zero profile for 120GMX). Lesson learned.
I'll reach out to Hornaday tomorrow , Pic of the bad lot.

Interesting. I have some AG on the shelf, just out of curiosity, what's the bad lot #?

Good news is that it sounds like you're well stocked with 6.5CM ammo!!

 

[Deplorable77]

Just a follow up for any of you that read or followed this. Hornady received and tested the ammo I returned and it would not chamber in their M1 platform either., it was indeed out of spec for 6.5.
They will be shipping out replacement A.G. as soon as it comes off the line. Fantastic service and communication from Hornady on this issue and no complaints on my end.