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Molon
11 July 2015, 13:13
Accuracy Evaluations of 14.5” AR-15 Barrels With Permanently Attached Muzzle Devices


The unwashed masses in my state are not allowed to own SBRs, therefore the shortest commonly available AR-15 barrels that I can legally posses are 14.5” barrels; with permanently attached muzzle devices that bring the overall length up to the legal length. For this article, we’ll be looking at four different chrome-lined, NATO chambered, 14.5” AR-15 barrels with permanently attached muzzle devices:

> Noveske 14.5” “Skinny” barrel

> Noveske 14.5” N4 “Light” barrel

> Bravo Company 14.5” “government profile” barrel

> Colt 14.5” M4A1 SOCOM barrel


The Noveske barrels evaluated have permanently attached Smith Enterprise Vortex flash-hiders. The Bravo Company barrel evaluated has a permanently attached BCM A2X flash-hider and the Colt M4A1 SOCOM barrel evaluated has a permanently attached Young Manufacturing flash-hider.

All of the barrels were evaluated utilizing free-float hand-guards and match-grade hand-loaded ammunition. All testing was conducted from the bench at a distance of 100 yards.

I conducted the accuracy (technically, precision) evaluations of the four different barrels listed above following my usual protocol. These accuracy evaluations used statistically significant shot-group sizes and every single shot in a fired group was included in the measurements. There was absolutely no use of any group reduction techniques (e.g. fliers, target movement, Butterfly Shots).

The shooting set-up will be described in detail below. As many of the significant variables as was practicable were controlled for. For these accuracy evaluations, I used one of my standard match-grade hand-loads topped with Sierra 55 grain BlitzKings. When fired from my Krieger barreled AR-15s, this load has produced ½ MOA 10-shot groups at 100 yards.




https://app.box.com/shared/static/n5uicctmu8ve7kxmht3zboy2inihdvzq.jpg



All shooting was conducted from a concrete bench-rest from a distance of 100 yards (confirmed with a laser rangefinder.) The barrels used in the evaluations were free-floated. The free-float hand-guards of the rifles rested in a Sinclair Windage Benchrest, while the stock of the rifle rested in a Protektor bunny-ear rear bag. Sighting was accomplished via a Leupold VARI-X III set at 25X magnification and adjusted to be parallax-free at 100 yards. A mirage shade was attached to the objective-bell of the scope. Wind conditions on the shooting range were continuously monitored using a Wind Probe. The set-up was very similar to that pictured below.




https://app.box.com/shared/static/xo4duzdgtp.jpg




The Wind Probe.

https://app.box.com/shared/static/lkg47ptc04.jpg







The Colt M4A1 SOCOM barrel


http://www.box.net/shared/static/dq2orr4r7z.jpg




A genuine Colt M4 SOCOM barrel is 14.5” long and has a medium contour underneath the handguards (not a heavy barrel profile). The barrel has a NATO chamber and a 1:7” twist. The SOCOM barrel has the typical M4 circumferential cut-out located approximately 1.4” forward of the gas block for the attachment of an M203, as well as rectangular shaped cut-outs underneath the handguards on the port and starboard sides of the barrel, located approximately 1.4” aft of the gas block, for the same reason. The SOCOM barrel employs the carbine length gas system.



http://www.box.net/shared/static/sh1g1d1ph2.jpg




http://www.box.net/shared/static/8m6luc1e9j.jpg




The barrel stamp located just aft of the flash suppressor reads:

C MP
5.56 NATO 1/7


http://www.box.net/shared/static/3vibt7g94a.jpg





The barrel has an “F” marked front sight base and a side sling swivel. The “F” mark is located on the port side of the front sight base.



http://www.box.net/shared/static/vthg89r4uq.jpg




http://www.box.net/shared/static/55o3qsd633.jpg





The SOCOM barrel will have a “date code” located immediately aft of the handguard retaining ring. The handguard retaining ring itself will also have cut-outs located at 4:30 and 8:30; again for the attachment of an M203.

The barrel will also have a small “O” stamp, that is located at the chamber section of the barrel, indicating a chrome-lined chamber and bore.




http://www.box.net/shared/static/3eoi24l667.jpg





Naturally, the SOCOM barrel will have M4 feedramps and there will be a numeral “4” stamped at the 3 o’clock position on the barrel extension.

http://www.box.net/shared/static/uu0b9h482l.jpg





Here are a couple pics comparing the SOCOM barrel to the standard M4 barrel.




http://www.box.net/shared/static/7c6rn7lhez.jpg





http://www.box.net/shared/static/65p2ey76g9.jpg




The Colt 14.5" M4A1 SOCOM barrel used in this evaluation was free-floated during testing using a Daniel Defense Omega free-float railed handguard. Using the match-grade hand-loads, I fired three 10-shot groups from the Colt SOCOM barrel at a distance of 100 yards. Those groups had extreme spreads of:

0.90”
1.02”
0.93”

for a 10-shot group average extreme spread of 0.95”. All three of the 10-shot groups were over-layed on each other using RSI Shooting Lab to form a 30-shot composite group. The mean radius for the composite group was 0.35”.

The smallest 10-shot group.

http://www.box.net/shared/static/r9jgrq14zn.jpg




The 30-shot composite group.

http://www.box.net/shared/static/rbirjox05r.jpg




http://www.box.net/shared/static/pc5x4tu58z.jpg





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Noveske 14.5” N4 Light Barrel


http://www.box.net/shared/static/if9xfp9b6u.jpg



For starters, Noveske’s nomenclature of “Light” for this barrel is somewhat misleading/confusing. When most shooters hear the term “light- weight” in regard to AR-15 barrels, they think of the “pencil” barrel profile of the original Colt M16/M16A1 and also the same light-weight profile of the Colt 16” carbine barrel found on the Colt 6520 and 6720. However, this is not the profile of the Noveske N4 Light barrel.


Colt M16/M16A1 barrel . . .
https://app.box.com/shared/static/x0cts9jy8awkdorf3h1hrbaxbnm55yxs.jpg




Colt 6520 16” light-weight barrel . . .
https://app.box.com/shared/static/9hz8ums473ej2niw3cikna798f0u5uvd.jpg


Noveske’s N4 Light profile was designed to produce better accuracy than a government profile barrel without adding any weight. The 14.5” and 16” N4 Light barrels have the same weight as Colt 14.5” and 16” government profile barrels.

As you can see in the pics below (16” version pictured), for the N4 Light barrel, Noveske has done away with the next-to-useless M203 (grenade launcher) cut-out found on the Colt government profile barrel. The N4 profile also has a more evenly distributed barrel diameter (and thus weight) fore and aft of the gas block journal, which moves the center of gravity of the barrel farther aft compared to a government profile barrel. This all makes for a superbly handling barrel.





Colt 6920 government profile barrel . . .
https://app.box.com/shared/static/j14x5puqrvltgj5qwwj718hhpasopkgd.jpg




Noveske 16” N4 Light barrel . . .
https://app.box.com/shared/static/mmtv78t6idf06vt21qpokip2o0rwpbnz.jpg





The reason that Noveske uses the “Light” nomenclature for their N4 barrels is simply because the N4 barrels are lighter than Noveske’s original medium contour stainless steel barrels.


The Noveske 14.5” N4 Light barrel is a cold hammer forged barrel. It has “M4” feed-ramps and a chrome-lined chamber and bore. The barrel has a 5.56mm NATO chamber and a 1:7” twist and has been high-pressure/magnetic particle tested; as the barrel stamp indicates. Contrary to erroneous Internet reports, the N4 barrel does not have polygonal rifling.


The barrel stamp . . .
https://app.box.com/shared/static/nnef26zvhhneds44z1tgcut3kec4ybx0.jpg




The Noveske 14.5” N4 Light barrel used in this evaluation was free-floated during testing using a Larue Tactical free-float railed handguard. Three 10-shot groups fired from 100 yards using match grade hand-loads had extreme spreads of:

1.029”
1.360”
1.275”

for a 10-shot group average of 1.22”. As above, I over-layed the three 10-shot groups on each other using RSI Shooting lab to form a 30-shot composite group. The mean radius for that composite group was 0.37”.



…..



Bravo Company 14.5” Barrel

https://app.box.com/shared/static/vb0ji49326ote5fkp77zanujjjeqx04v.jpg




This is the cold hammer forged (BFH) version of Bravo Company’s 14.5” barrel with a mid-length gas system. As can be seen in the pic above, this barrel has a government profile. This is a chrome-lined, NATO chambered barrel with a 1:7” twist. Bravo Company states that these barrels have been high-pressure/magnetic particle tested according to the current mil-spec.

The Bravo Company 14.5” barrel used in this evaluation was free-floated during testing using a Daniel Defense Omega free-float railed handguard.

Three, 10-shot groups of the match-grade hand-loads were fired in a row from the Bravo Company 14.5” barrel from a distance of 100 yards with the resulting extreme spreads:

1.58”
1.96”
1.50”

for an average 10-shot group extreme spread of 1.68”. The three, 10-shot groups were over-layed on each other using RSI Shooting Lab to form a 30-shot composite group. The mean radius of the 30-shot composite group was 0.49”



The smallest 10-shot group . . .

https://app.box.com/shared/static/v12ees2v20rebztan19154kxxo1why9o.jpg




The 30-shot composite group . . .

https://app.box.com/shared/static/ffljsglzv8wb6ron1oipq8kdlc7ncuwm.jpg



….









Noveske 14.5” “Skinny” Barrel

https://app.box.com/shared/static/w3os5lxh6oakyawvz3dpv364u3sg3jgv.jpg


Noveske’s “Skinny” barrel is their version of the light-weight “pencil” profile barrel. This barrel is a cold hammer forged barrel. It has “M4” feed-ramps and a chrome-lined chamber and bore. The barrel has a 5.56mm NATO chamber and a 1:7” twist and has been high-pressure/magnetic particle tested. The barrel has traditional rifling.


The Novekse 14.5” “Skinny” barrel was tested while wearing a Centurion free-float rail. For this barrel, I fired eight 10-shot groups in a row from the bench at a distance of 100 yards using the match-grade hand-loads. The extreme spreads for those eight groups were as follows:

1.78”
1.89”
1.68”
1.71”
1.81”
2.12”
1.60”
1.84”

for an average extreme spread of 1.8” and a composite mean radius of 0.55”.




…..


Some additional data for comparison . . .



https://app.box.com/shared/static/zy0a61s0qrl0aui5rtk1bfctrg4fqg05.jpg



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toolboxluis00200
11 July 2015, 13:38
Is it just me or is your dog in ever thred u make lol

gatordev
11 July 2015, 13:48
Interesting to see that both the Colt and the N4 "Light" seem to be consistent across multiple barrels. I've been really impressed with what my SOCOM can do with a non-FF rail (just a KAC RAS) and a 4x optic. And I've always been a fan of my N4 since day one.

Molon
11 July 2015, 14:13
Is it just me or is your dog in ever thred u make lol



[:D]



https://app.box.com/shared/static/k8sns0nrb9.jpg



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Molon
12 July 2015, 11:03
Some additional data for comparison added to the first post.

Will@AR15Hunter
31 July 2015, 13:26
Thanks for sharing Molon.

I'm still glad I purchased my 14.5" Colt SOCOM years back, based off of your barrel review. To this day, I think it's still my favorite rifle.

WHSmithIV
31 July 2015, 20:57
The dog belongs there - seriously!

Great info and a very nicely done comparison test. Thank you. I enjoyed reading it and seeing the results. In a 'perfect' environment (that doesn't actually exist in the real world), a rifle in a bench rest if locked down in that rest and can not move then fires 10 shots would have every single bullet going right through the same hole as the first bullet. It doesn't work that way though. Your test is very good proof of that.

Thank you again. I really enjoyed the write up and you did a great job in writing it up too.

DutyUse
1 August 2015, 22:45
I always enjoy reading your posts Molon. Superb write up and testing as usual.

I'm happily surprised to see the Noveske skinny holding its own vs the N4 light.

Edit: Not sure what barrels you have slated for testing in the future, but I would personally enjoy seeing what you could accomplish using various SBR length barrels

Dsledge
10 August 2015, 19:08
Molon, I have a question about your bench rest technique. Are you free recoiling the rifle? Are you shouldering it? Could you explain a little bit about your technique so us mortals could try and shoot as well as you from a bench? Assume i have the exact same bench equipment as you. If you dont mind.

Molon
12 August 2015, 13:09
Molon, I have a question about your bench rest technique. Are you free recoiling the rifle? Are you shouldering it? Could you explain a little bit about your technique so us mortals could try and shoot as well as you from a bench? Assume i have the exact same bench equipment as you. If you dont mind.




For my set-up, I’ve found that over the long-run, I get the best bench-rest consistency from my AR-15s by using a real hard hold; and by “over the long-run” I mean shooting and analyzing more than one-thousand 10-shot groups.

The stock is pressed very firmly into the shoulder and the pistol grip is grasped just short of causing muscle tremors. The cheek is pressed down into the stock very firmly. The whole rifle is pressed forward into the front-stop of the bench-rest as if loading a bipod on steroids and of course this must all be done in the same manner for every shot. Consistent follow-through is absolutely essential when shooting a semi-automatic AR-15 to obtain a high degree of precision.

A semi-automatic AR-15 is never going to shoot as precisely as a “blue printed” bolt-gun, but an AR-15 chambered in 5.56mm/223 Remington can do some remarkable things for a semi-automatic rifle.



https://app.box.com/shared/static/r35j7qm5i1.jpg




https://app.box.com/shared/static/pt7y91nj7y.jpg




https://app.box.com/shared/static/edqv78hn81.jpg




https://app.box.com/shared/static/qbpey0f4w4xdjb87d158zy0li2run72w.jpg






https://app.box.com/shared/static/c3nj830tjxcph7zq8vm7.jpg



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Dsledge
12 August 2015, 15:38
Wonderful. That was exactly what I was looking for. Thank you! On you control loads in your Krieger with 55 BlitzKings. What kind of velocity do you see? Have you seen a correlation between bullet speed and precision? As in slower projectiles tend to group better than faster?

gatordev
12 August 2015, 15:44
Disclaimer: I'm not near the shooter as Molon AND I didn't shoot 10 rounds, but here's what my SOCOM barrel did yesterday with a 4x optic @100 yards (6 shots). I'm sure if I had done a 10 shot group, it would have opened up a bit (due to shooter), but still, I'm happy with my barrel.

http://i840.photobucket.com/albums/zz322/gatordev/Public%20pics/SOCOM%20Family%20Pics/IMG_0487_zpscrsnmdyp.jpg

docsherm
12 August 2015, 15:47
Great post as usual.

toecheese
13 August 2015, 08:52
Very informative!!! I would think going pinned 14.5 with the new PDW stock would be a nice alternative to not being able to SBR.