Criterion hybrid that won’t shoot

S

SPRword

Private
Minuteman
Sep 24, 2022
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19
Minnesota
#1
Howdy gents. Though I’ve been active on other sites for years, I believe this is my first post here. I’m hoping some of the experts can help me with a 16” Criterion barrel that I cannot get to shoot.

This is actually my second criterion barrel, the first had the same issues and criterion did a great job taking care of me and swapping it out for the current barrel. It’s a carbine length gas system, 1/8 twist, hybrid profile. I have built and rebuilt this upper three times now, and criterion has rebuilt it once. I am using the Criterion supplied bolt, I am using a larue MBT trigger, and I and shooting exclusively off bags or a bipod. I cannot, under any circumstances, get this rifle to shoot below 1.5 MOA. I have tried Matech 77gr MK262, black hills 77gr MK262, some Freedom munitions 77gr reloads, M193, M855, and even some junk 55gr wolf. The 77gr freedom munitions loads are capable of 1.5-1.8 MOA. Black hills gets me about 1.5-2 minutes. Everything else is 3.5 MOA or greater.

There is no tension on the gas tube, I have tried two different gas system, all installed with a torque wrench, and have used both a geissele MK4 rail and an older Troy alpha rail, also installed to spec with a torque wrench. Criterion tried my receiver face, bedded the barrel, no success. I have taken it out of that upper and installed it into another upper with a trued receiver face, no success. I then took the barrel out and tried it in a different receiver without a trued face, same results. I have tried criterion’s supplied bolt, 2 or three other bolts, and yesterday, after exhausting everything possible, swapped the entire BCG, all with no success. Is 1.5-1.8 MOA all I can expect from this barrel?

For context, I would not consider myself an expert marksman, but I have built some extremely accurate AR15’s and can shoot them well. I have another 16” upper built with an older CHF/CL Rainier Arms barrel that I can consistently pull .9-1 minute groups with. I have shot quite a bit at extended ranges and would consider myself proficient in the basics of marksmanship such that if the rifle is capable of it, I can achieve sub-minute groups from a bench.

I should add, I have had nothing but positive experiences with Criterion. They have worked very hard to help me with this, but my troubles persist. Does anyone have any thoughts on what I may be missing, or what else I could try with this? I love the idea of a match grade chrome lined barrel which is what drew me to criterion, so I would hate to swap it out for a nitrided alternative if there something I can do to correct this. Thank you all in advance.
 
#2
What scope is on the rifle?
Have you tried any match grade ammo that’s not 77gr?
When is the last time you shot <1’’ groups with your other rifle and can you do it consistently? Have you taken both rifles out and shot them side by side? Shooting <1” with a gas gun can be tricky and it’s a skill that can perish quickly if you aren’t practicing consistently.
 
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#8
Thank you all for the suggestions. I have shot them both next to one another. I have used a trijicon accupoint 1-4 and a SIG Tango 6 2-12, I see similar results with both optics. I am capable of shooting sub minute groups consistently with my rainier build, as well as my SIG 716DMR with FGMM 175gr SMK’s. While there is always room for improvement, I do not believe the error is with me.

I have not tried any non-77gr match ammunition. It is possible that this barrel prefers something else, and I plan to pick up some other options next week to try. I would certainly prefer to make it work with 77’s though as that is what I currently stock.

For the record, I did not buy the second barrel, criterion provided it to me free of charge and they were very good about it. Has anyone else had issues with 77gr loads from their criterion’s?

Again, thank you all for your input. Has anyone had similar experiences? If so, how did you solve it? If you weren’t able to solve it, what chrome lined options would you all consider as replacements?
 
#10
Bolomauser said:
Thank you all for the suggestions. I have shot them both next to one another. I have used a trijicon accupoint 1-4 and a SIG Tango 6 2-12, I see similar results with both optics. I am capable of shooting sub minute groups consistently with my rainier build, as well as my SIG 716DMR with FGMM 175gr SMK’s. While there is always room for improvement, I do not believe the error is with me.

I have not tried any non-77gr match ammunition. It is possible that this barrel prefers something else, and I plan to pick up some other options next week to try. I would certainly prefer to make it work with 77’s though as that is what I currently stock.

For the record, I did not buy the second barrel, criterion provided it to me free of charge and they were very good about it. Has anyone else had issues with 77gr loads from their criterion’s?

Again, thank you all for your input. Has anyone had similar experiences? If so, how did you solve it? If you weren’t able to solve it, what chrome lined options would you all consider as replacements?
Click to expand...

Cheater load using a flat base varmint bullet and a lower powder charge 23-24gr sort of thing.
 
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#11
Hmmm, you installed the barrel with a torque wrench…. When I’ve swapped barrels all I did was get the barrel nut snug, then snugged it up a bit more until the gas tube lined up. For actual barrel torque for me it has to be under 25/30lbs. And yes I greased the threads.

Once the gas tube is installed the barrel nut can’t back off, this works for me
 
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#13
I had a 14.5" Criterion Core that didn't shoot super well either. I shot 1 5-shot group with 10 types of ammo at 100y. The best group was with Hornady 55gr FMJ handloads that I load for a different rifle, at 1.25". Other than that the results were similar to yours. Atlanta Arms 77gr AMU, Black Hills Blue Box 77gr, and Magtech 77gr all shot about 1.5" and were the best groups after the 55gr FMJ handloads. Our Hornady 75gr handloads, PMC Bronze 55gr, and IMI M193 shot 2". Then the other types of ammo shot from 2.25 to 3.4". I wasn't happy with its accuracy considering its reputation and that it weighed about 1.5oz more than a gov't profile 14.5". The bolt also didn't lock back with Atlanta Arms 77gr and the barrel profile prevented me from using the QD cup close to the receiver on a Centurion CMR Mlok handguard. I sold it and replaced it with a DD 14.5" which shot a better best 5-shot group and better overall across different types of ammo.
 
#14
I have a handful of their barrels that shoot really well. I haven't ran into one that doesn't yet. I have them in 300wm 6.5 creed, 6.5 grendel, 280, and a 223 on one of their blanks made by someone else.
 
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#15
There are usually 3 things that can cause problems,
gas port through a land slices off more copper on one side of the bullet.
Burr on the crown or crown off center if it has a 45* chamfer
The muzzle has swelled where the 1/2" threads were cut but Steve knows about this issue and in the past has always stress relieved the barrels twice.
I would borescope the barrel very closely and look for the first 2.

This type of crown has a 45* chamfer into the bore, it is easier to get an imperfect crown with type.


bad.jpg


This is a 11* crown without a 45* chamfer, much easier to cut a perfect crown if they single point cut this starting in the center and moving outward on the X axis.
perfect.jpg

BTW Keep torquing your barrel nuts to 40lbs, that barrel to receiver connection needs to be as rigid as possible.
 
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#16
Constructor said:
There are usually 3 things that can cause problems,
gas port through a land slices off more copper on one side of the bullet.
Burr on the crown or crown off center if it has a 45* chamfer
The muzzle has swelled where the 1/2" threads were cut but Steve knows about this issue and in the past has always stress relieved the barrels twice.
I would borescope the barrel very closely and look for the first 2.

This type of crown has a 45* chamfer into the bore, it is easier to get an imperfect crown with type.


View attachment 8121281

This is a 11* crown without a 45* chamfer, much easier to cut a perfect crown if they single point cut this starting in the center and moving outward on the X axis.
View attachment 8121285
BTW Keep torquing your barrel nuts to 40lbs, that barrel to receiver connection needs to be as rigid as possible.
Click to expand...
Thank you for this. I am going to order a bore scope when I get home. I am strongly considering, if this remains an issue, cutting the barrel down to 13.9/14.5 and pin/welding a surefire 3P on it. Perhaps the shorter length and increased rigidity can pull some extra little bit of precision out of it. If not, I guess it will have to serve as a beater. I took it out yesterday and fired it next to a cut down LE6920 that I was zeroing and was very disappointed when the Colt out shot it. Hopefully the bore scope can tell me more.
 
#17
I would sell it for cheap and count your losses. Even if you lose say 100$ it's pretty easy to put 100$ worth of ammo and your time into just one range trip and you have probably spent the equivalent time and money to buy a decent barrel messing with it. My gut is that those hybrid profiles are especially hard to get stress relieved etc properly & I doubt they sent you a dud as a warranty replacement. Criterion barrels aren't bad per se but the ones I had that shot really well were inspected and final chambered/headspaced by a gunsmith.
 
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#18
BCP said:
I would sell it for cheap and count your losses. Even if you lose say 100$ it's pretty easy to put 100$ worth of ammo and your time into just one range trip and you have probably spent the equivalent time and money to buy a decent barrel messing with it. My gut is that those hybrid profiles are especially hard to get stress relieved etc properly & I doubt they sent you a dud as a warranty replacement. Criterion barrels aren't bad per se but the ones I had that shot really well were inspected and final chambered/headspaced by a gunsmith.
Click to expand...
Not a bad idea. I’m sure I have double the cost of the barrel into this already just in ammo, much more if you count my time and the hours spent rebuilding.
 
#19
I’m sure you already confirmed that nothing is touching the barrel or gas block inside the hand guard, but you might also look at how much clearance there is. Barrels flex more than seems obvious when firing. You might look at the inside of the hand guard wherever the closest point of contact is and see if you can detect any signs of contact.

Failing that, I’d abandon it as soon as possible. I just went through a similar situation with a very high quality Valk barrel from a smith who is well known here. Together we tried everything. We just gave up a couple weeks ago and are rebarreling it. I’m too embarrassed to tell you how long I spent and how many rounds were expended trying to solve it. I wasted far more than the cost of another barrel in components trying to figure it out.
 
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#21
TimK said:
I’m sure you already confirmed that nothing is touching the barrel or gas block inside the hand guard, but you might also look at how much clearance there is. Barrels flex more than seems obvious when firing. You might look at the inside of the hand guard wherever the closest point of contact is and see if you can detect any signs of contact.

Failing that, I’d abandon it as soon as possible. I just went through a similar situation with a very high quality Valk barrel from a smith who is well known here. Together we tried everything. We just gave up a couple weeks ago and are rebarreling it. I’m too embarrassed to tell you how long I spent and how many rounds were expended trying to solve it. I wasted far more than the cost of another barrel in components trying to figure it out.
Click to expand...
Well I took your advice. I swapped it out this afternoon with a spare FN 14.7 I had. We’ll see how that one shoots this week. I can’t imagine it’ll be any worse. Hopefully someone else can get a hand load for this criterion that will run for them, I’d love to see it get used.
 
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#22
Bolomauser said:
Well I took your advice. I swapped it out this afternoon with a spare FN 14.7 I had. We’ll see how that one shoots this week. I can’t imagine it’ll be any worse. Hopefully someone else can get a hand load for this criterion that will run for them, I’d love to see it get used.
Click to expand...
Tomato stake dude.
 
#23
This thread made me take my CORE out last weekend. I was very relieved to see it still shooting 55gr blaster ammo into 1.5 moa consistently. Not sure why Criterion owners are all solidly in either the straight magic or hot garbage camp with nothing in between.
 
#30
All I have used since 2000 has been 8 twist barrels, 69s and 77s both shoot well. I had a 22 cal wildcat based on the 6.8 case (5.56x42) that would shoot the 75gr Amax under 1/2" with 4-5 different powders. Jason Peterson shot a 4.5" group at 1200yds at Strategic Edge with the same type of barrel and the 75gr Amax which is longer than the 77s.
 
#37
Douglas have always been considered real match grade blanks.
Douglas, Shilen, Pac Nor on the lower end
Krieger, Bartlein, Lilja, Hart on the upper end, Broughton, Rock and some others have retired.
 
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#39
TacticalPlinker said:
3 barrels, different brands
Click to expand...
Not trying to be a dick, but if you think about it you can see how statistically irrelevant that is. It means you've only had either one 8 twist or one 7 twist, and the fact that they were all different barrels from different manufacturers made by different people on different machines with different reamers, possibly at different price points, probably from different blanks means that a three barrel test is a non test.
If you've ever ordered two identical barrels at the same time you've likely seen firsthand that no two barrels are guaranteed to like the same bullets/loads regardless of twist rate.
 
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#40
On A serious note: Make sure your scope is good! Had a gun that shot great go to crap, then the gimbal in the scope broke!
Worse gun I ever owned: DPMS LR 308 went to the best gun I now own: put a gas block with a regulator went from a 1.5 MOA gun to a .375 MOA gun.
If hand loading, triple check what you are doing.
I process all of my cases the same for my F/TR, Tactical or semi rifles!
 
#41
TonyTheTiger said:
Not trying to be a dick, but if you think about it you can see how statistically irrelevant that is. It means you've only had either one 8 twist or one 7 twist, and the fact that they were all different barrels from different manufacturers made by different people on different machines with different reamers, possibly at different price points, probably from different blanks means that a three barrel test is a non test.
If you've ever ordered two identical barrels at the same time you've likely seen firsthand that no two barrels are guaranteed to like the same bullets/loads regardless of twist rate.
Click to expand...
Not making any other statement other than my own personal experiences. Since I supported Criterion enough to actually buy their CORE in 18 inch . So I don't have an ax to grind. I'm sure I'm not the only one who prefers 1/7
 
#42
TacticalPlinker said:
Not making any other statement other than my own personal experiences. Since I supported Criterion enough to actually buy their CORE in 18 inch . So I don't have an ax to grind. I'm sure I'm not the only one who prefers 1/7
Click to expand...
That's fair enough, and I'm certain you aren't the only one that prefers 7t. But my point is, when I ask people the reason they prefer it (and I do quite often) it almost always turns out to be based on non-data.
 
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#45
reubenski said:
I've always been confused why people think they need a 7" for an AR. If you look at normal twist rates an 8" is more than adequate. I think people picked up this idea from military rifles that used 7"'s but what they failed to differentiate is that is a military requirement based on a specific nose heavy penetrator. For the conventional bullets we shoot an 8" should give you better results.
Click to expand...

The 1;7" twist wasn't for a nose heavy penetrator. It was for a long nosed tracer. :ROFLMAO:


m856_tracer_001-2790965.jpg



...
 
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#46
Molon said:
The 1;7" twist wasn't for a nose heavy penetrator. It was for a long nosed tracer. :ROFLMAO:
Click to expand...
Could we just blanket statement and say that 7 twist is a requirement for a very specific bullet that's not in common use among civilians and thus far not being discussed in this thread?
And then can we agree that a 7 twist barrel is NOT a requirement for the 77gr match bullets being discussed?
 
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#47
I shot my 14.5 Criterion Hybrid next to my Colt LE6920 and both shot 77 grain very well, however, they were my handloads. I measured every single charge. Maybe try some 69 grain stuff and see if it prefers that? Im not that great of a marksman either. Loading my own made a tremendous difference. I dont think Ive ever shot factory match ammo.
 
#48
Bolomauser said:
Well I took your advice. I swapped it out this afternoon with a spare FN 14.7 I had. We’ll see how that one shoots this week. I can’t imagine it’ll be any worse. Hopefully someone else can get a hand load for this criterion that will run for them, I’d love to see it get used.
Click to expand...
Did you get a chance to try the FN 14.7 ?

And did you get a chance to bore scope the Criterion ?

I have my eye on another Criterion barrel w/ a CL bore.... this would be my first CL Criterion I will assemble . ( I have 2 other CORE's , just haven't gotten around to them yet )
FWIW, all my other Criterion's shoot well beyond my expectations. All AR based...2 in 6.5 CM, one in .308, and two in .223 Wylde.... so I hope the next one is a shooter as well. None are HBAR profile.
And FWIW, I have a 20" AR15 SS FN HF 5.56 1n7 barrel that flat out hates all the 77gr factory loads I tried ( pretty much all the factory loads available at the time ) except the 77gr SMK Creedmoor sports load, that one factory load will shoot great in it.
 
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#49
bfoosh006 said:
Did you get a chance to try the FN 14.7 ?

And did you get a chance to bore scope the Criterion ?

I have my eye on another Criterion barrel w/ a CL bore.... this would be my first CL Criterion I will assemble . ( I have 2 other CORE's , just haven't gotten around to them yet )
FWIW, all my other Criterion's shoot well beyond my expectations. All AR based...2 in 6.5 CM, one in .308, and two in .223 Wylde.... so I hope the next one is a shooter as well. None are HBAR profile.
And FWIW, I have a 20" AR15 SS FN HF 5.56 1n7 barrel that flat out hates all the 77gr factory loads I tried ( pretty much all the factory loads available at the time ) except the 77gr SMK Creedmoor sports load, that one factory load will shoot great in it.
Click to expand...
I did! I like it quite a bit. All I had at the time was some 55gr Freedom munitions .223, but I averaged between 1.5-2 minutes pretty consistently. I plan to take it out again later this month after I get some more time and see what it can do at range with some better ammunition. Thus far it’s much better than the criterion was.
 
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