Is this chamber issue or head space issue?

[SouthWest Guy]

just put together an new ar upper with NEA 18" 1:7 barrel,

testing ammo: A/E 223 55Gr, A/E 556nato 62Gr,

Accuracy: 2-3 MOA

barrel nut torqued to 50ftlb, swapped bolts from DPMS and Norinco, still have this bloomed shoulder issue, but i don't have 556 nogo gauge to check the head space. I am wondering if any CGNer have ever run into this issue.

Cases from left to right(fried from different barrel with same DPMS bolt): NEA,DPMS,Norinco

 

[D-Boy]

Your chamber is not good , clearly out of spec. Don't shoot that barrel.

 

[Countryboyz]

Far right brass looks ok to my old eyes, far left brass....not good. Sent you a pm. Looks like the barrel was not screwed in far enough on the left round, giving you the blooming. I am over by Capilano mall & would have time tomorrow to see it in person & give you a better idea!

If you don't have a head space gauge try using "plastigauge" it is a millwright tool for measuring the gap in gears....

 

[09outlander]

Am I right the brass on the far right was fired from a different barrel and the two on the left form the NEA barrel. If that is the case than it's a chamber problem with the NEA barrel.

 

[TheHowitzer]

I would think it would be a chamber issue. That sucks, sorry for the setback

 

[Hitzy]

It's the new NEA Weatherby shoulder chamber.....yeah, seems legit....

 

[yodave]

looks like it's within their specs........which may not be within industry specs

 

[tiriaq]

Exchange the barrel.

 

[just having some fun]

The case on the left when the chamber was being cut had a metal chip under the cutter

if it was purchased as a new get it replaced as defective

I have one similar and have been told by a excelent gunsmith that as long as brass does not jam it was ok// not great but just ok
not good for long brass life

 

[Glock4ever]

Without a measuring gauge to show the various sizes of the brass or where it is deforming out from, it would be difficult to say if you have a headspace issue or an improperly cut chamber. Three different barrels with the same bolt doesn't clearly indicate what the problem could be - if you improperly installed the NEA barrel it won't matter that the DPMS bolt is good to go with the Norinco Barrel. Have you removed the NEA barrel from the upper receiver and examined if there was any debris/metal shavings/etc that were perhaps stopping the barrel from seating all the way into the receiver? Does the bolt easily cam all the way shut?

 

[Trinimon]

Time to do a chamber cast with some cerrosafe.

 

[Ganderite]

My experience with NEA (a bad receiver) is that if you return it with a polite letter and a full explanation (sample brass), they will take care of it quickly.