NEA 7.5" AR barrel - an initial review
So my 7.5" NEA barrel arrived today. In full disclosure, I did not buy the barrel. It was acquired in a trade of product for services with the president of NEA, but it completely representative of what they are shipping to customers. I do not work for NEA and receive no monetary remuneration from them.
This initial batch of barrels have conventional rifling. I am told that the next batch they run will have the same polygonal rifling as their 10.5" and 14.5" offerings. The barrel is 5.56 chambered, 1:7 twist, and ARC+ treated.
Right out of the box you note that the finish is mottled light grey, not unlike glass-beaded stainless steel in appearance. It ships with the customary NEA poker chip.
https://www.milsurps.com/images/impo...DSCN3180-1.jpg
Markings are laser-engraved on the bottom of the barrel:
https://www.milsurps.com/images/impo...DSCN3181-1.jpg
Muzzle is nicely threaded with no machine chatter and the three muzzle brakes I tried fit smoothly (YHM Phantom GI A2 and NEA Hybrid). I gauged the threads and they pass 1/2-28-3A GO and NOGO.
https://www.milsurps.com/images/impo...DSCN3182-1.jpg
There was a small ring of metal around the base of the barrel extension locator stud when I unpacked the barrel. This should probably have been picked up by a QA person prior to shipping to me, but nevertheless, it came off when I pulled at it with a dental pick. I asked NEA about it and they indicated that this is a known issue on the first few barrels that shipped and it has been corrected on all future shipments.
https://www.milsurps.com/images/impo...DSCN3183-1.jpg
Here you see the barrel after a light wipe with an oily rag. The mottled look pretty much vanished, but it will remain a lighter colour than some people might prefer. In my case, I don't give a rat's @ss... lol.
https://www.milsurps.com/images/impo...DSCN3184-1.jpg
Here you see the locator stud after the ring of metal was easily removed:
https://www.milsurps.com/images/impo...DSCN3185-1.jpg
M4 feed ramps and a nicely transitioned chamber mouth:
https://www.milsurps.com/images/impo...DSCN3186-1.jpg
I'm going to assemble it on a new Aero Precision upper which is a standard GI spec forged 7075-T6 upper, Type III hard coat anodized. There is a little wear to the anodizing on the receiver threads and that is from trial fitting another hand guard, but this is a factory new upper that has never had a barrel installed (yet).
https://www.milsurps.com/images/impo...DSCN3188-1.jpg
The barrel goes right in without any mods and it went in TIGHT. I had to mount the receiver in soft jaws and give it a good shove to seat it. This is a good thing for accuracy. A slightly loose barrel to upper fit won't affect reliability if the barrel nut is torqued to spec, but it CAN affect accuracy if your optic are receiver mounted.
https://www.milsurps.com/images/impo...DSCN3189-1.jpg
I'm using a Troy free float battle rail. Here you see the barrel nut being torqued to 45 ftlbs. Spec is to torque between 30 and 60 ftlbs to achieve a tight fit and gas tube alignment. I used some PTFE lube on the receiver threads prior to torquing the nut.
https://www.milsurps.com/images/impo...DSCN3190-1.jpg
I used a YHM low-profile gas block. It would not fit on out of the package. I lightly rubbed the barrel journal with 600 grit emery paper to remove any imperfections and spun some 600 grit wet/dry inside the gas block on a drill to remove some of the parkerizing. I oiled the interface with a good gun oil and it just went on, very snugly by hand. I wrapped a piece of rubber sheet around it and rotated it back and forth as I slid it on to make it fit without resorting to metal punches. I believe that the YHM part had thick parkerizing on it. The tight fit is actually a good thing - the lock screws will keep it from loosening over time and were set with Red Loctite 222MS.
https://www.milsurps.com/images/impo...DSCN3191-1.jpg
The tool I made to polish inside the gas block bore:
https://www.milsurps.com/images/impo...DSCN3192-1.jpg
Fitted and gas tube (RRA pistol length tube from Questar) pinned:
https://www.milsurps.com/images/impo...DSCN3193-1.jpg
Rifle assembled onto a dedicated AP lower. I used an M16A2 carrier and will start with a Colt H2 buffer. Flash hider is an NEA hybrid.
https://www.milsurps.com/images/impo...DSCN3195-1.jpg
Range report to follow with both brass cased and steel cased ammo.
EDIT to include range report:
Got to the range today and put 300 rds through this PDW. 200 American Eagle 55 grain rounds and 100 MFS steel-cased 62 grain ammo.
https://www.milsurps.com/images/impo...DSCN3196-1.jpg
A couple factors were working against me:
1) I stupidly forgot to bring an iron sight adjustment tool, so the iron were useless for elevation; and
2) Something was wrong with my ancient aim point CompM2 and I could't get the damn thing zeroed - I think the windage turret is worn out.
As a result, please forgive that the groups are not in the centre of the targets.
Initial thoughts:
1) DO NOT do what I did and use an NEA hybrid brake on a 7.5" AR15. It WILL cause lots of microscopic still-burning powder to shower the shooter's face and generally cover the gun in specs of ash. YES, I did figure this out the hard way and thank god for good shooting glasses. The powder bounces off the front of the slats in the brake and comes right back at you. 7.5" down the barrel, it is still very much burning and not totally spent. I will have to switch to a SPEX, Noveske PIG, Dlask clone, or similar.
Check out the fine yellowish-white ash on the upper. The whole AR, my ball cap, my jacket, etc. was covered in this stuff.
https://www.milsurps.com/images/impo...DSCN3200-1.jpg
2) DO run an H2 or heavier buffer. I tried H, H1 and H2. The H buffer was ridiculous. The H2 made it manageable. You might even get away with a 9mm blowback buffer, but I didn't try it. This gun will keep the H2. I believe NEA is going to ship the PDW with an H installed - IMHO replace it right away with an H2. You'll be glad you did.
3) For only 300 rounds, this AR got DIRTY. It usually takes me close to 1000 rounds to get one as grimy as this one got. Lots of unburnt powder and gunk gets into the upper - more so than on guns with longer gas systems. Check this out to see what I mean. This was NOT dirty Norinco ammo either!
https://www.milsurps.com/images/impo...DSCN3202-1.jpg
https://www.milsurps.com/images/impo...DSCN3203-1.jpg
4) Less is not more. You need to oil these PDWs more than you would a carbine-length gas system. I like CLP, but your mileage may vary.
5) These WILL put a big smile on your face and draw onlookers with questions about your tiny little AR15.
Groups were not spectacular. It's a 7.5" gun and the 4MOA dot of the Aimpoint was completely covering my whole target (including the white part of the paper) at 100m. Guys shooting at 25m or 50m to test a gun always make me laugh... though for fun-shooting, this gun would likely come alive between 25m and 50m.
With a better optic or if I had used the irons, I think I could have shrunk these a bit. With a 7.5" tube though, I wasn't expecting much better. These were typical groups, though some of the 300 rounds I fired were just mindlessly pumping rapid-fire into the berm to test function and reliability.
https://www.milsurps.com/images/impo...DSCN3198-1.jpg
https://www.milsurps.com/images/impo...DSCN3197-1.jpg
https://www.milsurps.com/images/impo...DSCN3199-1.jpg
I got several stoppages in the first 20 rounds, presumably because no part of this gun had been fired before - all parts are virgin to this rifle except for the optic. The last 280 rounds were fired with no malfunctions and no stoppages of any kind.
