Am I just the only unlucky person to ever own an AR10? Ok, I am off to the range. I have about 150 rds of ammo, all FIT in the magazine which should mean all is well. Don't count on that. After maybe 10 rds or so, the thing won't go into battery again and needs a rubber mallet to get the almost seated round out of the chamber. The bullet was partially pulled from the lands by evidence of the scrape marks. Chamber brush and away we go again for another 15 rds or so....same thing. So, I use an OAL gauge and it calls for about 2.87 and a -.20 off the lands for 2.67 OAL. My ammo was all at 2.87 left over from a bolt action Tikka T3 Tac. BUT all ammo fit the magazines which means it should work. Armalite answered my questions with..."Buy better ammo....and we have never heard of this before...." I'm so lucky to in such a small group of shooters having this problem I guess.
So Armalite said it was cheap ammo?
What brand and type?
It may be worth it to buy a box of Federal Gold Medal Match and see what it does, if you still have issues with that then I'd say the chamber needs some work. If you have issues with a quality ammo then I'm sure Armalite will back up the warranty.
I sent in a M15TBN upper for a misaligned rail and mentioned that the chamber was leaving some odd marks on the fired brass, no malfunctions just some circular marks. They polished the chamber while they had it and the issue went away.
I'd definitely try some better quality ammo. The 2.87 OAL seems too long to me. Usually the max OAL is 2.86. Of course it depends on the bullet design and how far the ogive is from the lands in the barrel.
The ammo was far from cheap, and usually a good brand name. Winchester. I have lost faith in this company and this AR10bTBNF will be up on the market soon. I don't have a particular grief with them, just don't like what has happened and the answers I got from them. ALL my rifles have to work ALL the time, and I cannot own something I have no confidence in 100% reliability. The company answers were way too brusque and uncaring about my 1,700.00 or so investment in their company. I know they invented it and developed it but they are not the only players in town anymore. A company cannot live on it's reputation forever, and in MY eyes only, the rep is becoming a bit tarnished. I will obviously continue my connection with the .308 as I feel it is the best battlefield cartridge/ammunition ever made so far.
2.87 is the figure from the gauge, and if you back that off the .20 you get an OAL of 2.67 which would/should work fine. BUT the defining fact is that all ammo must fit into the magazine. All of my ammo fit in the magazine, and therefore should all work.
I agree that Armalite should do something about it. It is also disturbing if they copped an attitude when you talked with them. It does sound like an issue with the chamber. I generally load mine to 2.80 on the nose and have never had any problems with it. Never had any problems with factory either. What bullet type were you shooting? Pointed soft points by chance? Very doubtful that would be it. I am guessing the chamber is out of spec. Will it load and cycle ammo manually? Man sorry to hear about your problems.
The cartridge OAL is just one factor. The freebore in the chamber and the bullet ogive are also factors. My guess is you may be jamming the ogive of the bullet into the lands. The extracted rounds that did not chamber will clearly show the land marks if this is the case. Armalite is likely not the problem, not saying they can not make a mistake but with the gages used in manufacturing they are likely not the problem in this case.
Dick what ammo are you using, really just need specifics weight, bullet, brass. I don't know why you have not mentioned it but please fill in the gaps here.
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