AR10 pressure signs?

[joehunt]

Hey Guys.
I’m pretty green to these rifles. (Pretty good around bolt guns)
I’m getting ejecter swipes on low loads all the way up to mid loads.
Factory rounds coat the bolt in brass there is some much coming off.
No other pressure signs. Primers are not flattened. Maybe getting a slight bit of cratering
at the higher end. I read that they make high pressure bolts for these? Is this what is needed?
Or is the ejector spring just way stronger on these then a bolt gun.
It’s a stag10 with a BA Barrel in 6.5 Creedmoor it was a Creedmoor from the factory.
Loads I shot last night
Virgin Hornady brass
Cci br2
Lapua-Scenar 139gr
39-41gr of accuracy 4350 in half grain increments.
41 grains produced a sub 1/2 moa 5 shot group at 100yrds.

Thanks for the help
Joe

 

[griffin86]

It’s overgassed, I would get a superlative adjustable gas block. Every Creedmoor I build gets one.

The bolt is trying to unlock while there is still pressure.

 

[rugbydave]

^ Yeah, all the factory Stag 10s I've seen so far are way overgassed, mangles the brass pretty bad. Adjustable gas block is the answer.

 

[joehunt]

I don’t think it has an adjustable block on it. Will definitely look in to it.
Thanks

 

[joehunt]

It definitely does beat on the brass right now.

 

[griffin86]

I don’t think it has an adjustable block on it. Will definitely look in to it.
Thanks

Before you order one, I would remove your gas block and measure the diameter of gas block journal. Should be .750”, .875”, or .936”. The hardest part is the gas tube roll pin, and it’s not that difficult to tap in.

 

[joehunt]

Ok will do.
Is the superlative atms the only way to go? What’s the advantage of venting the gas vs choking the gas?
Thanks s bunch guys
Joe.

 

[griffin86]

Ok will do.
Is the superlative atms the only way to go? What’s the advantage of venting the gas vs choking the gas?
Thanks s bunch guys
Joe.

They are less likely to erode the screw and have it seize. The Superlative, I think, can be finer tuned. It goes from 0-4.5 turns. Each turn is 4 clicks IIRC.

 

[joehunt]

Ones on the way.
Thanks a again

 

[joehunt]

Just a little feed back!
Got the adjustable gas block, installed it and adjusted it two clicks past just leaving the bolt open.
The rifle recoils way nicer now and marks up the brass a lot less. I have now also disassembled the bolt and give it a slight polish. It had a pretty good bur around the ejector hole. I’m looking forward to testing it out now.
I love shooting this rifle. Hope I get to keep it after next month elections.
Joe