Criterion 16” CORE Barrel Accuracy Evaluation





Well over a decade ago, the late John Noveske was the impetus for bringing modern AR-15 barrel profiles to the civilian market.  His 16" CHF N4 barrel profile has the same weight as a government profile barrel of the same length, but it has a more intelligently designed contour that places more of the weight of the barrel from the chamber to the gas block journal and does away with the M203 cut-outs.



Over the last several years we’ve seen the emergence of barrels produced by multiple manufacturers with the specific objectives of balancing weight distribution, heat absorption and handling characteristics while at the same time endeavoring to improve upon the accuracy/precision of old school barrel profiles of similar weight.  Criterion Barrels CORE series of barrels is a prime example of this modern approach to profiles for AR-15 barrels.

The Criterion 16” CORE barrel reviewed for this article has a stripped weight of exactly 1 pound, 12.0 ounces.  This is the same weight as a Colt 16” government profile barrel.  As with the Noveske CHF N4 barrel, the CORE barrel profile has done away with the useless M203 cutouts.  More of the barrel material has been shifted to the aft of the barrel for a “continuous taper” profile.  The gas block journal for the CORE barrel is 0.625”.


The 16” CORE barrel . . .






The barrel stamp reads:  CRITERION 223 WYLDE 1-8





The date code on this barrel reads:  08/21.





The CORE barrel is button-rifled and the bore is hand-lapped.  The bore and chamber are chrome-lined.  As pictured above, the barrel has a 223 Wylde chamber, a 1:8” twist and utilizes a mid-length gas system.  The gas port diameter gauged at 0.078”.








For comparison, a larue 16" predatar barrel has a gas port diameter of 0.082".






The gas block journal of the CORE barrel has a single dimple contralateral to the gas port.





The barrel extension has M4 feed-ramps, although it is not marked as such like a Colt barrel extension.




The crown.








I installed the Criterion 16” CORE barrel in a new Colt cage-code M4 upper receiver and free-floated the barrel with a Geissele MK16 rail.  A new JP Enterprises EnhancedBolt closed on a 1.4646” headspace gauge and did not close on a 1.4666” headspace gauge.














I conducted an accuracy (technically, precision) evaluation of the Criterion 16” CORE barrel from my bench-rest set-up following my usual protocol.  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).

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

All shooting was conducted from a concrete bench-rest from a distance of 100 yards (confirmed with a laser rangefinder.) The free-float hand-guard of the rifle 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 accuracy evaluation of this barrel began with factory loaded Federal 77 grain Gold Medal Match ammunition.  One of the first groups fired from this barrel had an extreme spread of 0.18”.  That group is pictured below.






The very next group fired from this barrel had an extreme spread of 1.5”.  That 10-shot group is pictured below.





A 10-shot group with an extreme spread of 1.5” is perfectly acceptable for a 16” chrome-lined AR-15 barrel with a weight of 1 pound, 12 ounces.  However, this barrel isn’t broken-in yet.  The bore-scope image shown below was taken prior to any shots being fired.  It shows the sharp tooling marks on the lands in the leade, which run perpendicular to the direction of bullet travel.  






For the barrel to shoot to it’s potential, the sharp edges of these tool marks need to be “burnished” out.  So, I continued shooting 10-shot groups using a variety of factory loads and hand-loads.

For comparison, the bore scope view shown below is from the leade of a Colt M4A1 SOCOM barrel that's been fully broken-in.




As the fired round-count for the CORE barrel approached 150, the size of the groups shrank and became more consistent.  At this point, I fired the three 10-shot groups “of record” using 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.









The three, 10-shot groups fired in a row from the Criterion 16” CORE barrel from a distance of 100 yards had the following extreme spreads:

1.15”
1.09”
1.13”

for an average 10-shot group extreme spread of 1.12”.  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 0.39”.


The smallest 10-shot group . . .






The 30-shot composite group . . .














….........


for comparison . . .


Colt 6920 Barrel Accuracy



If you were given the task of designing an AR-15 barrel profile with an eye towards accuracy, handling characteristics and heat tolerance, along with a length requirement of 16 inches and a weight restriction of 1 pound 12 ounces, the odds are that the last idea that you would come up with would be the ubiquitous 16” government profile barrel with M203 cutouts that is found on the Colt 6920.  (How’s that for a run-on sentence?)  The profile of the 6920 barrel has more to do with accommodating an M203 grenade launcher than the attributes listed above.

The Colt 16” government profile barrel has a NATO chamber, M4 feed-ramps and is chrome-lined.  The barrel employs a carbine length gas system.  The stripped weight of this barrel is 1 pound, 12 ounces.








These barrels are typically found with a 1:7” twist but were also produced with a 1:9” twist (AR6920DC).




The 6920 barrels that I have owned have had an “O” stamp at the chamber end of the barrel and some form of a date code stamped just proximal to the gas block journal.








The government profile barrels found on the Colt 6920 tend to show more variation in accuracy/precision from barrel to barrel than heavier profile barrels.  The test results shown below were obtained with free-floated barrels.

One Colt 6920 barrel tested from my bench-rest set-up at a distance of 100 yards using match-grade hand-loads produced three 10-shot groups fired in a row that had extreme spreads of:

1.42”
1.19”
1.56”

for a 10-shot group average extreme spread of 1.39”.  The mean radius for the 30-shot composite group was 0.44”.



The smallest 10-shot group . . .




The 30-shot composite group . . .




Another Colt 6920 barrel tested under the same conditions as described above produced three 10-shot groups fired in a row that had extreme spreads of:

1.59”
1.55”
1.73”

for a 10-shot group average extreme spread of 1.62”.  The mean radius of the 30-shot composite group was 0.54”.


......








…

Oh Shit. Molon is back, and I'm in on first.

Always love to read your review.

I have been waiting for this one!

Okay, just finished reading your review. Looks like the Criterion is a smidge more accurate than the Noveske N4. Whew! That means I don’t need to buy the Criterion barrel.  Right? Lol.


Accuracy Evaluations of 6 Different Noveske barrels

Noveske 16" N4 light Recce

Noveske's chrome-lined barrels have 5.56mm NATO chambers and 1:7" twists.


I performed an accuracy evaluation of my Noveske 16” N4 Light Recce upper following my usual protocol.  Testing was performed from a distance of 100 yards.  Firing was conducted from a concrete bench with the free-float handguard resting in a Sinclair Bench Rest.  The rear stock of the rifle rested in a Protektor bunny-ear bag.  Wind conditions were monitored using a Wind Probe.  A Leupold VARI-X III set at 25X magnification and adjusted to be parallax free at 100 yards was used for sighting.

Using hand-loaded, match grade ammunition I fired three, 10-shot groups in a row.  The extreme spreads of those groups measured:

1.29”
1.18”
1.31”

for a 10-shot average extreme spread of 1.26”.   I over-layed those three groups on each other using RSI Shooting Lab to form a 30-shot composite group.  The mean radius for the composite group was 0.37”.

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

I found Molon’s individual review of a Noveske N4 light barrel but it’s missing a lot of pics.

Decent MR.

Got any "after" bore photos?

But not as accurate as the Colt M4A1 barrel.

You are correct.

0.39 against 0.35 MOA for 30 cool shots.

Yeah this was certainly a write up I’ve been looking forward to. Thanks!

As being pretty well rounded in my ignorance, my take away from this is to not immediately judge a barrel “out of the box” before it has had a chance to break in.

I love these kind of reviews.  Thanks Molon.

when I first joined, I used to run google script codes to find your posts on ARF. It’s good to see you back in tech forums, putting solid data in every post for all of us. Appreciate the work you’ve put in!

Awesome work dude!

Just goes to show how upgrading and modernizing things usually results in worse performance than the standard mil-spec parts they’re supposed to improve upon.

@molon
Did you happen to snag velocities by chance? Thanks for the write up.

How about we get a statistically significant sample size before drawing that conclusion?

Nice write up thanks Molon

for comparison . . .


Colt 6920 Barrel Accuracy



If you were given the task of designing an AR-15 barrel profile with an eye towards accuracy, handling characteristics and heat tolerance, along with a length requirement of 16 inches and a weight restriction of 1 pound 12 ounces, the odds are that the last idea that you would come up with would be the ubiquitous 16” government profile barrel with M203 cutouts that is found on the Colt 6920.  (How’s that for a run-on sentence?)  The profile of the 6920 barrel has more to do with accommodating an M203 grenade launcher than the attributes listed above.

The Colt 16” government profile barrel has a NATO chamber, M4 feed-ramps and is chrome-lined.  The barrel employs a carbine length gas system.  The stripped weight of this barrel is 1 pound, 12 ounces.








These barrels are typically found with a 1:7” twist but were also produced with a 1:9” twist (AR6920DC).




The 6920 barrels that I have owned have had an “O” stamp at the chamber end of the barrel and some form of a date code stamped just proximal to the gas block journal.








The government profile barrels found on the Colt 6920 tend to show more variation in accuracy/precision from barrel to barrel than heavier profile barrels.  The test results shown below were obtained with free-floated barrels.

One Colt 6920 barrel tested from my bench-rest set-up at a distance of 100 yards using match-grade hand-loads produced three 10-shot groups fired in a row that had extreme spreads of:

1.42”
1.19”
1.56”

for a 10-shot group average extreme spread of 1.39”.  The mean radius for the 30-shot composite group was 0.44”.



The smallest 10-shot group . . .




The 30-shot composite group . . .




Another Colt 6920 barrel tested under the same conditions as described above produced three 10-shot groups fired in a row that had extreme spreads of:

1.59”
1.55”
1.73”

for a 10-shot group average extreme spread of 1.62”.  The mean radius of the 30-shot composite group was 0.54”.






…

It would appear the criterion barrel improved upon the colt barrel.

It would appear that way, but that .078” gas port on a .625” gas block journal is excessive and not by a little bit, and the Wylde chamber doesn’t bring anything positive to this type of barrel.

The .05” smaller mean radius is not a significant enough difference to really be attributed to the barrel’s design/construction, and it’s not relevant to the intended use of that type of barrel.

Criterion just built another overgassed, Wylde/whatever chambered, commercial barrel in an overcrowded sea of commercial junk.

ETA:  That barrel with a gas block is $358 + shipping + wait time from Criterion.  I’d take a carbine gassed Colt barrel over that all day every day, not even considering that Colt barrels are easy to get for about $140 less.

My sample size is 20 years training and wrenching on ARs.  I’m not an super SME, but I’ve seen a bit.  

.078” port on a .625” journal with a Wylde chamber is a barrel built for light use with light .223 ammo or/and gassed to ‘cycle everything’, IE: it will eject with the internet gun guy’s A5H-whatever buffer, 87 coil tactical spring, and Tula steel cased ammo.

That guy is a big segment of the market, but he can choose from any barrel maker and get something like that for half the price.  

Criterion placed themselves in same space as the budget brands on specs, but way over what it costs to get a better barrel for hard/actual use.

mmm 30 shot composite groups with mean radius given.  Molon have you shot the hybrid line of barrels in comparison to the core?

I have the 16 inch core barrel on my coyote hunting gun. I have gotten very similar accuracy results that molon got.

I have always said mine is overgassed, even though criterion markets their core barrels as gassed for suppressed use. Turns out it is just marketing. While this is a good barrel, I think there are other good options that are gassed more conservatively and get very similar accuracy results.

I was going to ask about the gas port size, but didn’t. However, it seems that my “gut feeling” was right.

I am just a long time AR enthusiast with several courses under my belt. I have picked up some great info from this site from some knowledgeable folks, so I know enough to get myself in trouble. Lol.

It’s great to have people like yourself and Molon on-board that have valid data and real world experience to share and to explain why things are “good to go” or where the design fell short and expose weakenesses.

@samuse do you believe the Noveske 16” middy N4 light barrels are overgassed? And what would be the “right” gas port diameter for a 14.5”/16” middy? I wanted to have my 16” N4 light barrel cut down to 14.7” but the Noveske rep advised against it saying the gas port was good for the 16” length, not something shorter.

I can restrict gas flow. I cannot improve the accuracy in a given barrel. Ymmv.

The accuracy of the Core barrel vs the 6920 was so close that you couldn’t give a nod to either one, even if all you did was Molon style accuracy evals.

I would strongly prefer a proper 5.56 chamber and 5.56 appropriate size port. Because I shoot 5.56 and it gets hot, dirty, and stays that way for long while.  

I don’t doubt that it’s a quality barrel, but I don’t see anything about it, other than profile, that could be considered an improvement over a 16” Colt carbine  barrel.  

Thank you for the time and effort. This is a great write up.

Agreed.

@samuse But doesn’t the chamber also play a part in the overall accuracy of a barrel? If so, how much? And how much does it affect reliability? I know this has been discussed ad nauseum here, and I have an idea as to what your answer may be, but I’m curious to hear what you have to say.

@Molon also wondering what your overall thoughts are as well.

I am sincerely asking, but I know that this is derailing the thread a bit.

i have a 12.5 core. i have not done precision tests or accuracy tests. it wears an EXPS on top.
i does operate with H2+blue PERFECTLY.
i did get a BRT tube for mixed use suppressed, i have yet to shoot it with the new tube, but i did get a reduced sprinco just in case.

going towards the comments about how colt is still better etc, thats fine. hang some weight on the end and lets see which has less POI shift with a can. which one balances better. i think thats what the CORE is marketed towards. i have yet to test with my sandman as its still in jail at 223 days

i like your tests molon. i follow them every time you post.
do you have a suppressor that you can use to compare POI shifts?

^ Lol. With that gas port and chamber they aren’t thinking about suppressors at all.

Hi,
   How is the gas port size related to the journal size?  
Thanks,
           Mark

Hi,
   How is the gas port size related to the journal size?
Thanks,
          Mark

From what I understand is that the thinner wall will get hotter and erode faster leading to even more gas drive.

You can conduct virtually no significant comparative analysis between the Criterion and Colt precision with the given data. With what, two loads?  You need to do a handful with different quality ammo to determine max precision along with mean and mode values etc.

These are good data points, showing that neither are bad and both can at least provide precision that is acceptable for most carbine use cases. But it doesn’t necessarily show the full potential of either barrel.

not entirely true, good blanket statement. alot of people run adjustable gas when building, so their port doesnt mean shit to be honest. i for one do not use adjustable gas, i feel they are a unpredictable variable that can fail. murphys law. why i tune with buffers and tubes.
nevertheless, with the actual contour of the barrel, id love to see if it would make a difference, wouldnt you?

If i am not mistaken, samuse isn’t arguing that the Criterion isn’t better because it’s accuracy isn’t a helluva lot better, but, rather that the Colt is better because the Criterion has a bigger gas port and a smaller diameter gas journal that will be much more affected by gas erosion and will overgas the system even more over time. At least that I what I am getting from what he wrote, but I could be completely wrong.

My experience has been the same. Definitely over gassed, especially suppressed. I'm going to be putting a BRT gas tube on mine. Very accurate for what the barrel is. Mine loves the ADI 69gr SMK's.

Exactly this.

If they don’t disclose gas port size and tell you that you’re gonna need an adjustable block or a BRT tube to run full power ammo / suppressed, then they’re not about it.

I like the contour of the barrel a lot. A lot better than my 16” M4 profile carbines.

So what would have been the more logical choice for a gas port on this barrel, .073?

i agree 100% on the gas. i could be more tame on the 16", but on my 12.5, blue+H2, its absolutely perfect, being a lefty no comment how it is suppressed.

id love to see some testing on the profile though as i was saying initially before, that is what im trying to say, not trying to say anything else.
im very curious how hanging a can off the end affects accuracy with their contour.
maybe we can get lucky and see some POI testing by Molon, his tests are fantastic and full of detail.

I like .071” on a 16” mid, but yeah, .073” would have been a lot better.



I kinda think that running extra power springs and heavier than H buffers is a band-aid solution to make it run more than it is ‘tuning’, especially on a brand new barrel.

There’s a few barrel makers out there that do it, but they’re few and far between.  

I just don’t like starting out overgassed and running heavier stuff on the back end because it’s only going to get worse.  I recently replaced a still good shooting 6920 barrel at somewhere around 13-15K rounds because it had gotten a little harsh as the cases went by.  It had a hard short life and spent the last half with an H3 buffer. I want one that runs right with an H right out of the box because they don’t last forever.

I can't speak on the longer systems, but my 12.5 core is gassed fine. I'm around 5k through it and there hasn't been any accuracy degrading yet. I'm not going to derail this anymore-if somebody would like to continue I'd be happy to start a new thread.

This is a nice feature that prevents muzzle device shims from shifting around during assembly. What is the downside?

I really enjoy your accuracy tests please keep them coming!

Thanks for the review Molon.

As I see it, the great value in these barrels is the balance and their ability to shoot nearly all ammo quite well. Overgassed? Probably. Absolutely the most accurate barrel ever? Of course not, and neither is the Colt SOCOM.

Haters aside, I think it's a step forward, picking up where Noveske left off. BCM tinkered with it a little with their enhanced medium weight fluted, which is a great barrel too. Good to see long-known bolt gun barrel principles making their way into the AR world.

I really like the profile, I don’t understand why it’s not more common.  Heck, why is it not the most common ??

How does the Wylde chamber differ from Noveske chamber?

The fact that these "enhanced" profiles are still something you have to go looking for is baffling to me. Govt profile is doing nothing for us and socom isn't particularly helpful unless you're mounting a tube to it, which 99% of us are not.

Thank you for your well conducted and presented tests. Always best in class.

Thanks for posting these tests @molon . I could read your evaluations all day.

Thank you Molon! For 20 years I have thoroughly enjoyed your amazing contributions to ARFCOM. Your posts are truly a great gift. We are all grateful for your time and thoughts.