AR-10 in 6.5 CM Having problems with bolt not closing

[Vmax97]

I have a new Armalite AR10 in 6.5 CM and have an issue with many rounds getting stuck or bolt not closing and case is stuck. I started using a small base die to resize brass thinking that would solve all my problems but I think there might an issue with bullet profile. I am reloading some more test rounds at are 2.760 inches AOL to see if that will help.

Anyone else seeing these types of issues and have resolutions?

 

[mac86951]

Gas key tight? Any chance the gas tube is misaligned/fouled to BCG?

I'd say get a snap cap and open the upper and try to close the bolt by hand. Lots of sub-systems could cause resistance to closing; so this way as you address each sub component you can determine which it was.

-Mac

 

[Jeff Porter]

Factory ammo or only reloads? Will the BCG fully close if you just let it fall by gravity. ( Take the upper off the lower and invert)

 

[misser]

what with empty sized brass ?

 

[jds holler]

Are you seeing any particular or peculiar scratches or scrapes on your ejected brass that might indicate a rough spot in the chamber?? jd

 

[Bill K]

If you have used the small base die and the loaded rounds are sticking and/or not allowing the bolt to fully close and lock.
Then make sure the brass is trimmed to proper trimmed length and also make sure the bullet used it not jamming into the lands, either could be the problem.

 

[Vmax97]

I figured out the problem. I needed to bump the shoulders about .004 and they run great.

 

[Park ranger]

I figured out the problem. I needed to bump the shoulders about .004 and they run great.

How does the gun shoot? I was looking at one

 

[Vmax97]

How does the gun shoot? I was looking at one

It shoots great, Now. I found an Armalite AR-10 at a great price and got it. The only down side is I have to separate my AR10 brass from my 6.5CM bolt brass now.

 

[Coyotefurharvester]

I often run my 223/20p ar's 0.0035-0.004 bolt clearance, especially in the winter. As I don't want to mess around with a forward assist or a live round needing mortoring. When I go shoot prairie dogs all the ammo is at or 0.0001 under the low step on my Lyman ammo checker. Than the ammo can be used in both gas/bolt guns. I have not had a case separate.