Larue 16" Stealth barrel with mid-length gas system, Larue low profile gas block. BCM bcg. Stag Arms upper & lower. The rifle fires and cycles fine but ejects the brass at the 1:00 position. Upon inspection of the brass it has a dent in the sidewall on every case in approximately the same spot on every case. From inspecting the rifle it appears the cases are hitting the rear of the ejection port opening and not the deflector. In y'alls opinion, would you try a different recoil spring and buffer to correct the problem or go with an adjustable gas block?

Curious, did you try different ammo?

I would measure/inspect the gas port to diagnose overgassing issue.  If out of spec, return barrel.

If in spec, an adjustable gas block, heavier buffer, heavier spring, or m16 bolt carrier, or any combination.

IMHO an adjustable gas block would also be an upgrade .

3:00 to 4:30 is ok ejection if you have standard components, and did your part.

Shouldn't  have to "fix" a new rifle.

And you can't swap known good parts because this is your only AR.

Which brings us to the root of the actual problem..

You need MORE AR's !!!

If it cycles fine, and it groups fine, who cares where the brass ends up?

Over Gassing can lead to many other problems.

Ejection angle is a symptom.

It can be a problem at a range if you like to pick up your brass, or have someone to the right of you.

A brass catcher is the fix for me.

overgassing


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1.  It's fine.
2.  AR's run in one condition:  overgassed; undergassed and they don't run.
3.  You could try a heavier buffer (H2 is pretty much the standard these days) and/or a stronger recoil spring.
4.  If I felt compelled to tinker with it for some unknown reason (after all, it works) I would talk to LaRue first.
4.  The last thing I would do is disassemble a brand new LaRue stealth upper URG.

+1 on the H2 buffer. Adjustable gas block should not be needed as your gas system length is appropriate for barrel length.

Obviously you are already runninh a quality FA BCG (BCM), so no need to change that out.

If symptoms persist after the buffer swap then send the barrel back to LaRue and have them take a look at it.

My money is on the H2 solving said "issue".

Let's see those dents.

Edited to remove bad link

I can't figure out how to upload a picture. Be patient

Hope the dents show up.



The ammo is Federal 223 rem. 55 gr. FMJ

My stag upper does that. Carbine buffer carbine gas 16". I haven't checked my brass on my new midlength build but I can tell it's WAY softer shooting.

If you watch slow motion videos of AR15 operation, you will see that the middle dent in ejected cases comes from the exact orientation of the case as it strikes the edge of the deflector just outside the back of the ejection port. Changing any of a number of variables will alter the orientation of the case and may reduce or eliminate the dent. Ejector spring force, bolt velocity during extraction, extractor tension, all work together to determine the orientation of the case as it ejects.

Ejecting to 1:00 oclock though usually means significantly excess energy. If you had an adjustable gas block that would be a good thing to try. Maybe Larue is drilling extra large gas ports to accommodate the ignorant like the one youtube blathering idiot that assembled a Larue barrel wrong.

Late to the party. Had the same issue.
18 inch bbl. rifle length and still a little overgassed. Ejecting at 1:00 to 2:00 using American Eagle 223. Also looked like a flame thrower.
Changed to H2 buffer and Wolff XH spring and got it to 2:00 to 3:00 and left it.
However, PMC 223, no flame and ejects at 4:00. The balance is good now.
Make sure you can properly and consistently cycle high and low powered ammo just in case