Black River Tactical 16” Cold Hammer Forged Optimum Barrel Accuracy Evaluation

[Molon]

Black River Tactical 16” Cold Hammer Forged Optimum Barrel Accuracy Evaluation

Black River Tactical has sold at least three differently constructed versions of their 16” Optimum barrel. This article showcases the cold hammer forged version that’s constructed of 4150 CrMoV steel. This barrel has a chrome-lined bore and chamber and a manganese phosphate exterior finish. The BRT CHF Optimum barrels have a 1:7” twist and a 5.56mm NATO chamber. The barrel has laser engraved markings that read:

BRT 5.56 1/7 HF CL-22J

I used a Colt reference bolt to check the headspace of the chamber on this Optimum barrel. The bolt closed on a 1.4646” headspace gauge. The bolt did not close on a 1.4696” gauge. Fired brass had a measured nominal headspace of 1.469”. A dummy round that meets SAAMI specifications easily seated completely into the chamber and dropped easily out of the chamber.

A 15” x 0.217” straightness gauge passed smoothly through the bore of the barrel. The land-to-land diameter at the muzzle gauged at 0.2191”.

The barrel extension has M4-type feed-ramps, although the extension is not marked as such like Colt barrels.

The muzzle has a slightly recessed crown. The barrel does not have a recess cut between the base of the muzzle threads and the shoulder of the barrel.

The following picture shows a borescope image of a CHF Hodge Defense barrel, which is manufactured by Fabrique Nationale. There’s nothing unusual about the appearance of the bore of this barrel as it has the typical bright pewter-ish appearance of a chrome-lined AR-15 barrel.

The next borescope view shows the throat of the BRT CHF Optimum barrel. Both the chamber and the bore of this barrel have a dark grey “coated” appearance to them. BRT claims that these barrels are “finished with an advanced hard chrome lining process”. The owner of BRT has refused to answer questions about any of this.

The 16” BRT Optimum barrel weighs approximately 1 pound, 11 ounces. For comparison, the 16” government profile barrel found on the Colt 6920 weighs 1 pound, 12 ounces.


The Optimum barrel has a pseudo-tapered profile. The barrel tapers from just forward of the chamber to just aft of the gas block journal, but unfortunately, at that point the barrel diameter swells for a 0.750” gas block journal. The shoulder for the handguard end-cap has a diameter of approximately 0.845”. The picture below compares the gas block journal of the Optimum barrel to the 0.625” gas block journal of a 16” Criterion CORE barrel (which weighs 1 pound, 12 ounces).

On the positive side, the gas block journal of the Optimum barrel mic’d at 0.7497”. The bore of the BRT low profile gas block that I used for this build had a gauged diameter of 0.7499” creating an excellent fit between the gas block and gas block journal. Another feature of the BRT low profile gas block is the diameter of the gas tube channel. It gauged at 0.1801” giving it a good fit with the 0.1798” BRT gas tube. These attributes contribute to an efficient gas system.



With a new AR-15, it's not at all uncommon to see a fair amount of fouling coming from the juncture of the gas tube and gas block due to gas leakage at this location. The carbon fouling will usually seal this leakage after several hundred rounds have been fired. Due to the close fit of the BRT components, there was hardly any fouling noted at this location.

The BRT gas block . . .

After 300 rounds had been fired through the barrel . . .

The gas block journal on the Optimum barrel is intended for use with low profile gas blocks only. It’s approximately 1” in length, so you won’t be able to use an A2 front sight base with this barrel. The gas block journal of the Optimum barrel comes with a single dimple contralateral to the gas port for positioning and fastening the gas block.

The most notable feature of the 16” CHF Optimum barrel is its intermediate-type gas system; meaning the length of the gas system is in between that of a standard mid-length gas system and a standard length rifle gas system.

BRT has referred to their intermediate-type gas system as both an extended length system and an intermediate length system in their description of this barrel. For the ease of discussion for the rest of the article I’ll be referring to the BRT gas system on this barrel as an intermediate length system. Be aware that there are multiple intermediate-type gas systems on the market with varying lengths. As an example, the BRT intermediate gas system is slightly shorter than the Noveske intermediate gas system found on Noveske’s 18” SPR barrels.

The next two pictures will give you an idea of how the BRT intermediate gas system compares in length to other common AR-15 gas system lengths.

The next picture demonstrates the dwell time (technically dwell length) of the 16” BRT Optimum intermediate gas system compared to other common gas systems found on the AR-15.

BRT refuses to provide prospective customers with the diameters of the gas ports on the CHF Optimum barrels so that they might make informed purchasing decisions. The diameter of the gas port on this 16” Optimum barrel gauged at 0.081”.

BRT recommends using the A5H0 buffer for shooting unsuppressed with this barrel. I’ve found the A5H1 to be more suitable for shooting with a mix of 5.56mm loads and quality 223 Remington loads

I installed the BRT Optimum barrel in a Bravo Company upper receiver. For those of you who might not be familiar with the BCM upper receivers, they are intentionally made under-sized in the section of the bore that accepts the barrel extension. This requires a thermal fitting with the barrel extension and creates such a tight fit that it’s not possible to pull the components apart by hand and eliminates any play between the barrel extension and upper receiver.


The Optimum barrel was free-floated in a Bravo Company 13” MCMR M-LOK handguard with a V Seven titanium barrel nut. I rounded out the upper receiver group with a BCM Mod 4B charging handle, a Forward Controls Design flash hider and a Geissele bolt carrier group.


On a side note, the Geissele bolt carrier group has some interesting dimensions. The diameter of the bolt tail fails to meet the US mil-spec, but in a good way. The mil-spec for the bolt tail calls for a diameter of 0.2503” plus or minus 0.0002”. The diameter of the Geissle bolt tail is 0.2507”. This bolt tail forms an exemplary gas seal with the bolt tail channel inside the bolt carrier (0.2514” on the Geissele carrier) contributing to the efficiency of the gas system.

continued in the next post . . . .

 

[Molon]

I conducted the accuracy (technically, precision) evaluation of the 16” BRT cold hammer forged Optimum barrel after performing a 200 round break-in of the rifle and then a thorough cleaning of the barrel and operating components. There were no malfunctions of any kind during the break-in period nor during the accuracy evaluation.

This accuracy evaluation 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). Pictures of shot-groups are included for documentation.

The shooting set-up will be described in detail below. As many of the significant variables as was practicable were controlled for.

All shooting was conducted from a concrete bench-rest from a distance of 100 yards (confirmed with a laser rangefinder.) A fore-end adaptor attached to the free-float handguard 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 used. Wind conditions on the shooting range were continuously monitored using a Wind Probe. The set-up was very similar to that pictured below.

The Wind Probe . . .

The first 10-shot group of record was fired using IMI M193. Prior to shooting this group several fouling rounds were fired with this ammunition. The 10-shot group had an extreme spread of 2.4” with a mean radius of 0.78”

The next group was fired using factory loaded Nosler 77 grain Custom Competition ammunition. Several seasoning shots were fired with this load prior to shooting the group of record. This 10-shot group had an extreme spread of 1.56” with a mean radius of 0.44”.

The final load used in this accuracy evaluation was one of my standard match-grade hand-loads topped with the Sierra 55 grain BlitzKing. This hand-load has produced ½ MOA 10-shot groups at 100 yards when fired from my Krieger barreled AR-15s. I’ve been using this load as a baseline in accuracy evaluations for decades and it has shot well in almost every AR-15 barrel that I’ve tested with it.

Prior to shooting the following groups, the barrel was given a light cleaning. As before, several fouling rounds were fired prior to shooting the groups of record.

Three 10-shot groups of the 55 grain BlitzKing load were fired in a row from the BRT 16” Optimum barrel at a distance of 100 yards with the resulting extreme spreads:

1.250”

1.232”

1.204”

for an average 10-shot group extreme spread of 1.229”. These three 10-shot groups were overlayed on each other using the software program RSI Shooting Lab to form a 30-shot composite group. The mean radius for the 30-shot composite group was 0.35”.

The smallest 10-shot group . . .

The 30-shot composite group . . .

After shooting the three 10-shot groups listed above, I fired an additional five, 10-shot groups, for a total of eight 10-shot groups. The average 10-shot group extreme spread for all eight groups was 1.227”. I overlayed all eight of the 10-shot groups in RSI Shooting Lab to form an 80-shot composite group The mean radius for the 80-shot composite group was 0.37”.



The 80-shot composite group . . .

Lastly, for any Internet Commandos in our viewing audience toady, here’s a pic of a sub-½ MOA group fired from the BRT Optimum barrel at a distance of 100 yards. The group has an extreme spread of 0.35”.

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[TheOE800]

Between not QCing their subcontractor’s work and not providing specs, BRT is real low on my list.

 

[346ci]

I like the intermediate gas system idea but would go with a ARP barrel in that price range. I do want to try one of their eztune gas tubes on my 6.8.

Thanks for taking the time to post the results.

 

[MontanaMan]

Excellent write-up, as usual, Sir.................thanks for posting it.

Regardless on any shortcomings from the company, the results of the barrel are pretty impressive with an 80 shot composite group with a mean radius of .37 for a chrome lined barrel being pretty decent, IMO.

The owners BS about the special chrome is likely just that & his refusal to talk about it is likely because he simply doesn't know.

The appearance of the "as plated" chrome ring around the breech end of the barrel is quite shiny & looks pebbly with nodules (not a good thing); if the barrel was similar, as plated, then they've done some good work, likely with lapping as it shows to be fairly smooth with no "as plated" surface showing in the bore / throat photo.

If it was dull or gray from plating, typically, that's not a good thing, but chromium tends to take on a dull grayish finish when lapped or honed, depending on the type of grit & the size of the grit particles.

I've dealt with virtually every type of chrome in existence on a technical level for many years ranging from basic single catalyst baths to complex catalyst diamond co-deposited baths.

I'd be willing to bet that FN plated the barrel & surprised if they didn't............................operating a plating system these days is a difficult thing, because of the permitting required to even build the facility, to all the monitoring required while in operation...............small business generally can't afford that kind of investment unless they have fairly high volume production utilization.

MM

 

[Alaska]

BRT barrels not even on my radar !

 

[matt33]

These reviews are awesome.

 

[Alaska]

I am leaning toward the Noveske 16.1” Recon barrel with the M249 chrome lining .

 

[Molon]

I am leaning toward the Noveske 16.1” Recon barrel with the M249 chrome lining .

Noveske 16” N4 Barrel Accuracy Evaluation

I’ve posted short reviews of Noveske N4 Light barrels in the past, so for this article we’re going to take a more in-depth look at the Noveske 16” N4 Light barrel. 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 . . .

Colt 6520 16” light-weight barrel . . .

The stripped-weight (no flash hider, no front sight base/gas block, just the barrel and barrel extension) of the Colt 16” light-weight barrel is 1 pound, 6 ounces. The stripped-weight of the Noveske 16” N4 Light barrel is 1 pound, 12 ounces; which is the same stripped-weight of the Colt 16” government profile barrel found on the ubiquitous Colt 6920.


Colt 6920 government profile barrel . . .

Noveske 16” N4 Light barrel . . .

As you can see in the pics above, 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 16” barrel.

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. For comparison, the Noveske 16” medium contour Recon barrel has a stripped-weight of 2 pounds, 2 ounces and as mentioned above, the 16” N4 Light barrel has a stripped-weight of 1 pound, 12 ounces.


The Noveske 16” Recon barrel . . .

The Noveske 16” N4 Light barrel is a cold hammer forged barrel. It has a mid-length gas system, “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 . . .

The mid-length gas system . . .

For this evaluation, 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.

Three, 10-shot groups were fired in a row from the Noveske 16” N4 Light barrel from a distance of 100 yards with the resulting extreme spreads:

1.29”
1.18”
1.31”

for a 10-shot group average extreme spread of 1.26”. 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 0.37”.

After firing the above three groups, I fired an additional five, 10-shot groups in a row for a total of eight, 10-shot groups fired in a row. The average extreme spread for all eight of the 10-shot groups was 1.24”. I over-layed all eight of the 10-shot groups on each other using RSI Shooting Lab to form an 80-shot composite group. The mean radius for the 80-shot composite group was 0.39”.





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[Alaska]

Thanks for the info
I went with the Noveske light Recon 16.1” barrel with the 249 lining from Noveske

2nd choice was Douglas 16” from High Cal Sales.

 

[Molon]

These reviews are awesome.

Muchas gracias.

...

 

[Alaska]

The barrel replacement went very well
Noveske Light Recon 16” and MK 14 13.5” rail fit perfect on the Colt carbine.
Went and tested fired the combination of the “G” Super 42 spring and H buffer kit with Surefire Warcomp closed time brake and the intermediate gas system sure makes a smooth shooting platform.

 

[Tackelbarry]

What am I missing? When reading the reviews it looks like the BRT performed as well or better than the Noveski. Am I interpreting this correctly?

 

[matt33]

Muchas gracias.

...

It might not be my place to say, but you should consider starting a youtube channel or something similar. I've read your reviews for many years and find a ton of value in them, I'm sure a ton of other people do as well. 9 Hole Reviews actually referenced you on a recent SOCOM vs. gov't barrel youtube video. On the entire internet, I've never found information as useful and detailed relating to ammo and barrel real-world performance. Thanks for doing it bro!

 

[JS8588]

It might not be my place to say, but you should consider starting a youtube channel or something similar. I've read your reviews for many years and find a ton of value in them, I'm sure a ton of other people do as well. 9 Hole Reviews actually referenced you on a recent SOCOM vs. gov't barrel youtube video. On the entire internet, I've never found information as useful and detailed relating to ammo and barrel real-world performance. Thanks for doing it bro!

All that AND he's a world-class counter troll. Second the motion he starts a YouTube/Rumble channel

 

[Molon]

It might not be my place to say, but you should consider starting a youtube channel or something similar. I've read your reviews for many years and find a ton of value in them, I'm sure a ton of other people do as well. 9 Hole Reviews actually referenced you on a recent SOCOM vs. gov't barrel youtube video. On the entire internet, I've never found information as useful and detailed relating to ammo and barrel real-world performance. Thanks for doing it bro!

Thanks for the kind words and the suggestion. I have considered starting a channel before, I'm just not sure if it would be the best format for the data that I post. I can pack a lot of data into an article with writing, pictures, graphs and tables that only takes 5-10 minutes to view.

...

 

[JS8588]

Thanks for the kind words and the suggestion. I have considered starting a channel before, I'm just not sure if it would be the best format for the data that I post. I can pack a lot of data into an article with writing, pictures, graphs and tables that only takes 5-10 minutes to view.

...

I wonder if TFB or TTAG would be interested in picking up your work. Alternatively, the Gun Collective. I'm sure there are others, but those are the 3 that jump to mind.

 

[Molon]

These reviews are awesome.

Muchas gracias.

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