Stag10 6.5CM chewing up brass? Photos & Video Clip

[quikcolin]

Hey guys,

I'm a new shooting, just built a Stag10 with a 20" 6.5 Creedmoor barrel, Brownell's BCG, Stag buffer spring, and Superlative adj. gas block.

Took the monster to the range for break in this morning and after 4 shots had the gas block adjusted to spit out brass at 3:30ish. Shooting great, but the brass looks a little rough. The bottom of each cartridge has nicks and chew marks on it from (I'm assuming) ejection?

Is there anything I can do?

Also, I removed a chambered, none fired cartridge and the bullet had a few deep scratches on it, from chambering I'm assuming? As it slides into the chamber maybe? Not sure?

See pics & Video

Is this normal?
Thx!

VIDEO OF EJECTION

 

[loveha]

Can we get a picture of the claw on the extractor? I'm guessing it's super sharp.

Also sharp feed ramps.

 

[VegasHKShooter]

Do you have an adjustable gas block?
If not, I would highly recommend getting one.
You can tune the gun down a bit and it will help your brass significantly.
You are a bit overgassed right now, and it shows on your brass.

 

[Darqusoull13]

If adjusting the gas down to ~3 o clock ejection looks like that I'd do as loveha suggested and check your extractor. It's kind of hard to tell with the light shining but it does look like you're getting a decent ejector mark as well so you might still be unlocking a touch early.

You can also swap out the Stag buffer for a JP heavy 308 Silent Captured Spring. More mass will delay the unlocking and the SCS will smooth out the cycle.

 

[quikcolin]

Do you have an adjustable gas block?
If not, I would highly recommend getting one.
You can tune the gun down a bit and it will help your brass significantly.
You are a bit overgassed right now, and it shows on your brass.

I do, a superlative adjustable gas block. Tuned her up today to a 3:30 ejection.

Can we get a picture of the claw on the extractor? I'm guessing it's super sharp.

Also sharp feed ramps.

Is that something that can be “filed” without screwing anything up? I’ll get some photos tonight

 

[quikcolin]

If adjusting the gas down to ~3 o clock ejection looks like that I'd do as loveha suggested and check your extractor. It's kind of hard to tell with the light shining but it does look like you're getting a decent ejector mark as well so you might still be unlocking a touch early.

You can also swap out the Stag buffer for a JP heavy 308 Silent Captured Spring. More mass will delay the unlocking and the SCS will smooth out the cycle.

I’m going to snap a few more pics tonight and hopefully that will help with the diagnosis

 

[VegasHKShooter]

Getting an AR “tuned” to eject at a certain point is a HUGE fallacy. There are many things that go into correct gas, and I promise you, 3:30 ejection isn’t really all of it.
I know many people believe there guns need to eject a certain way. That’s just not fact.
I’m betting if you’ll shut the gas block totally off, to where the bolt doesn’t open at all, then shoot one round, adjust, shoot again until the bolt just locks back, then go one or maybe two clicks for a cushion, your gun will smooth out.
I have a GA Precision GAP10, and my brass looks almost perfect when it lands. I tuned it like that.
I go 2 clicks past lock back just to give myself some cushion. Running dirty,
different ammo etc.
Just trying to help, but don’t get pulled into thinking 3:30 ejection means all is well.

 

[loveha]

I agree with Vegas, that ejection map/pie chart is useless.

Do what he suggested with starting closed and opening slowly till it locks back consistently with another one or two clicks more for a cushion.

As for filing the claw, it can be buffed I think?
Not sure how to go about that. Feed ramps can be buffed as well I know that much for certian.

 

[quikcolin]

Getting an AR “tuned” to eject at a certain point is a HUGE fallacy. There are many things that go into correct gas, and I promise you, 3:30 ejection isn’t really all of it.
I know many people believe there guns need to eject a certain way. That’s just not fact.
I’m betting if you’ll shut the gas block totally off, to where the bolt doesn’t open at all, then shoot one round, adjust, shoot again until the bolt just locks back, then go one or maybe two clicks for a cushion, your gun will smooth out.
I have a GA Precision GAP10, and my brass looks almost perfect when it lands. I tuned it like that.
I go 2 clicks past lock back just to give myself some cushion. Running dirty,
different ammo etc.
Just trying to help, but don’t get pulled into thinking 3:30 ejection means all is well.

Is this done with a single round in the magazine?

 

[loveha]

Is this done with a single round in the magazine?

Yes, as you are looking for bolt hold open.

 

[Anthonyc]

If your bolt is from stag, make sure you have the right bolt size as well. Stag sent me the wrong bolt sizes for a 224 Valkyrie 2 times in a row... third time was a charm..

 

[quikcolin]

If your bolt is from stag, make sure you have the right bolt size as well. Stag sent me the wrong bolt sizes for a 224 Valkyrie 2 times in a row... third time was a charm..

I have a Brownells black nitrate BCG ?

 

[VegasHKShooter]

Yes, as loveha said: you are looking to shoot one round and see if the bolt locks back. You then open the AGB one click at a time until you JUST get the bolt to lock back on the empty mag. Once you get bolt lock back, you go one or two more clicks.
That will give you a little cushion for ammo changes, dirty gun, etc.

By doing this, you get the gun as soft as it can be, and still function correctly.
I definitely notice the 6.5CM has plenty of gas to give you. ? It can definitely be turned down a bit.
You will immediately notice a difference on your shoulder and your brass. ?

 

[quikcolin]

Yes, as loveha said: you are looking to shoot one round and see if the bolt locks back. You then open the AGB one click at a time until you JUST get the bolt to lock back on the empty mag. Once you get bolt lock back, you go one or two more clicks.
That will give you a little cushion for ammo changes, dirty gun, etc.

By doing this, you get the gun as soft as it can be, and still function correctly.
I definitely notice the 6.5CM has plenty of gas to give you. ? It can definitely be turned down a bit.
You will immediately notice a difference on your shoulder and your brass. ?

Thanks you! I’ll do that! I’ll report back in a week or so and let you know how it goes

 

[quikcolin]

Hey guys!

I adjusted my gas block as recommended. My brass is coming out brand new, and the recoil is much better! Only thing is that the ejection is at about 1-1:30. Is this okay?

 

[Anthonyc]

Hey guys!

I adjusted my gas block as recommended. My brass is coming out brand new, and the recoil is much better! Only thing is that the ejection is at about 1-1:30. Is this okay?

I wouldn’t worry about it too much. Some of my guns do this depending on the loads I use (light vs hot). Although, I’m no expert with adjustable gas blocks...

 

[loveha]

If your brass looks good, and recoil is fine, and your bolt locks open on last round, then you're good.

Like I said, ejection pattern is irrelevant.

 

[quikcolin]

If your brass looks good, and recoil is fine, and your bolt locks open on last round, then you're good.

Like I said, ejection pattern is irrelevant.

Perhaps a heavier buffer would help? It's a bit annoying as the brass flyings into the grass in front of the bench and it takes ages to find the brass in there. I have a brass bag catcher thing, but don't always use it

 

[loveha]

That could possibly help. Would probably have to open the gas up a little to compensate for the added weight.

 

[quikcolin]

Would a heavier buffer cause the rifle to have MORE recoil?

 

[loveha]

More mass so most likely.

 

[quikcolin]

More mass so most likely.

To my surprise. It’s actually the opposite. Slows things does and reduces the sharp slap. Makes recoil more manageable