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[ARCHIVED THREAD] - Criterion CORE Accuracy Evaluation (Page 2 of 5)
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Quoted: @sdrake What would the better gas port size be? And what about the gas port size for a 14.5” middy?? Without derailing this, what other manufacturers out of the box have correctly sized gas ports for civilian use that also tick boxes for accuracy and maneuverability/profile? I've read that DD's 16" is .073, but most manufacturers don't post this information. I have a Centurion Arms 13.7" at .075, even that was a little gassy before swapping it onto my A5H2 lower setup. Is there a tipping point diameter size where it would become unreliable unsuppressed for 16" and 14.5" midlengths? I know there's got to be a spreadsheet somewhere |
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Quoted: @sdrake What would the better gas port size be? And what about the gas port size for a 14.5” middy?? For a gas block journal of .625", somewhere in the neighborhood of .069-.072 would be more appropriate imo, especially for suppressor use. For 14.5" middy, I like my Hodge barrel ported at .074-.075. Runs fine with Wolf Gold .223. URGI spec is .076 on the DD barrel, I believe. |
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I love a good Molon thread!! Has anyone compared the Larue Stealth barrel? I recently bought one and have been impressed so far although it may be apples/oranges since it is a heavier profile. In my experience, the accuracy difference between my best barrel (Noveske stainless 18" or Larue Stealth 16") .vs my Bushy, Colt, or PSA is maybe .50-.75MOA assuming ammo it really likes. Also, "journal" is the thickness of the barrel area at the gas port? This is a new measure/dynamic for me so I have learned something new. |
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Quoted: I love a good Molon thread!! Has anyone compared the Larue Stealth barrel? I recently bought one and have been impressed so far although it may be apples/oranges since it is a heavier profile. In my experience, the accuracy difference between my best barrel (Noveske stainless 18" or Larue Stealth 16") .vs my Bushy, Colt, or PSA is maybe .50-.75MOA assuming ammo it really likes. Also, "journal" is the thickness of the barrel area at the gas port? This is a new measure/dynamic for me so I have learned something new. In my experience the stealth barrel is more precise. My 18in stealth was between .5 and .75 with match ammo. My 16in Criterion is .75-1.0 with the same ammo. |
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Quoted: Lol.  It would be cool if you could organize all the info you have put together into an ultimate barrel buyer’s guide. It would pretty much answer all the questions that the manufacturers should, but don’t. I’m still patiently waiting for Molon to publish his book! 
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Quoted: https://www.ar15.com/media/mediaFiles/28568/criterion_core_barrel_leade_before_and_a-2148265.jpg For comparison, the bore scope view shown below is from the leade of a Colt M4A1 SOCOM barrel that's been fully broken-in. https://www.ar15.com/media/mediaFiles/28568/colt_m4a1_socom_barrel_leade_broken_in00-2148264.jpg ... How many rounds would it take to get it 'fully broken in?' |
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Quoted: How many rounds would it take to get it 'fully broken in?' Every barrel is going to be different. For a chrome-lined barrel, I typically fire 200 rounds before doing an accuracy evaluation. As demonstrated with the Criterion CORE barrel, the groups tightened-up around the 150 round mark. ... |
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Quoted: Also, "journal" is the thickness of the barrel area at the gas port? This is a new measure/dynamic for me so I have learned something new. The gas block journal is specifically just the area on the barrel milled out for a gas block. It is not just the diameter, but also has a length value. Some journals have a length that only allows for small gas blocks, whereas others are longer to allow for mounting a front sight base. |
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Hi, So I've got a 20" Core barrel with a rifle length gas system. All this talk is making me wonder. I won't be using a suppressor so what would be the recommended gas port size for a 20" rifle gas? I don't have pin gages of the proper size but the port size falls btw..089" and .093". Thanks, M. |
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Maybe dumb question as I obviously don’t know as much about the details involved in the original post(which is awesome by the way!). BUT what the chances of another bullet style/name brand, weight, etc, producing better results? If I remember right, the original post spoke of 2 maybe 3 different loads? I was always taught buy the bullet the specific barrel shoots the best = if it matters enough to the owner then try until you run out of options or money etc. From high end pellet guns, .22lr rifles to bench guns, I’ve never documented a group size unless I’ve tried “X” amount of different bullets/loads. Sometimes even the same make and model will even prefer different bullets. Just random thought. I could have easily missed it in the original post or I don’t know better. |
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Quoted: 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. This is some improvement over the M4 profile barrel at the same weight. It's not quite as good in Molon's testing as the M4A1 barrel, but it's also not meant to be compared to that. It's meant to be compared to the standard M4 profile, like the Noveske N4. In that respect, it is indeed a bit better. ETA: Not by a lot, granted, and there are other factors, but to say it's "worse" than the M4 barrel is just misleading. At a minimum, it's just as precise or a tiny amount more, and it'll be a lot less muzzle-heavy for better balance in the rifle overall. I'd be curious to see if anyone makes a similar type barrel that's a counterpart to the heavier M4A1 tubes, and if that's any improvement. |
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That profile is nice and makes sense, but practically, it’s cosmetics. It has zero effect on function or reliability, and near zero effect on accuracy. The gas port size and possibly the chamber on that barrel are a real detriment to reliability unless you do something to correct it. |
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Quoted: That profile is nice and makes sense, but practically, it’s cosmetics. It has zero effect on function or reliability, and near zero effect on accuracy. The gas port size and possibly the chamber on that barrel are a real detriment to reliability unless you do something to correct it. Barrel profile is way more than cosmetics dude. |
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Quoted: It's not quite as good in Molon's testing as the M4A1 barrel, but it's also not meant to be compared to that. Correct. The 14.5" M4A1 weighs more than the 16" CORE barrel. It's meant to be compared to the standard 16" M4 profile, Correct. like the Noveske N4.The Noveske N4 does not have a government/M4 profile  ... |
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Quoted: Quoted: It's not quite as good in Molon's testing as the M4A1 barrel, but it's also not meant to be compared to that. Correct. The 14.5" M4A1 weighs more than the 16" CORE barrel. It's meant to be compared to the standard 16" M4 profile, Correct. like the Noveske N4.The Noveske N4 does not have a government/M4 profile https://www.ar15.com/media/mediaFiles/28568/criterion_core_barrel_accuracy_compariso-2160926.jpg ... Pardon. I perhaps phrased that poorly. I was trying to say that the CORE is like the N4 in that it's meant to be an improved contour vice gov/M4 at the same weight as the M4. |
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The barrel looks like it'll keep its stiffness even when heated up based on its profile. It looks the 16~18" CORE would make for a lightweight varmint gun or SPR with some additional accurizing via shim or bedding. Given your own testing, what do you think the purpose of the CORE series is? Criterion's own description is a string of buzzwords imo and doesn't really clarify what the intended purpose of the barrel profile is. Also, how tight was the barrel extension to the receiver when it was being installed? I wonder if shimming might get rid of some of the random flyers. Your groups are excellent so it looks like the fliers are rifle-caused. |
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Quoted: If accuracy was the same, would you rather have an overgassed tight chambered taper or a properly gassed and chambered M4 profile? Quoted: Quoted: Barrel profile is way more than cosmetics dude. If accuracy was the same, would you rather have an overgassed tight chambered taper or a properly gassed and chambered M4 profile? Depends on what I'm doing with it. Regular M4 profile is going to be more noodly in certain shooting positions, with a can hanging off, etc. |
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Quoted: I have not. Do you use the same 55 blitzking load in all your posts that show it used in testing? Ala are these tubes per barrel when you do your evaluation or just your standard load for the Krieger and shoot it in everything? I was looking at your 10 shot eval of bcm elw bfh with 52 SMK and that question popped in my tiny brain. |
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Quoted: Do you use the same 55 blitzking load in all your posts that show it used in testing? When conducting my formal accuracy evaluations, I typically shoot several different loads in the barrel, including factory loads and some of my standard handloads, before shooting the groups "of record." More often than not, my handloads for the 55 grain BlitzKing show the best precision for the barrels being tested. On occasion, one of my other handloads shows a slight edge in precision from a particular barrel, such as the 52 grain MatchKing, so I'll use that load for the groups "of record." ... |
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Quoted: When conducting my formal accuracy evaluations, I typically shoot several different loads in the barrel, including factory loads and some of my standard handloads, before shooting the groups "of record." More often than not, my handloads for the 55 grain BlitzKing show the best precision for the barrels being tested. On occasion, one of my other handloads shows a slight edge in precision from a particular barrel, such as the 52 grain MatchKing, so I'll use that load for the groups "of record." ... Thank you sir. |
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Quoted: Casting Pearls Before Swine: My Years Posting on ARFCOM by Molon They Couldn't Handle The Truth by Molon Pit of Despair: Doing Yeoman's Work On A Forum by Molon LOL. I was thinking of using one of my sig-lines for the title of the book: In God We Trust. Everyone else must post data. or All that is necessary for Trolls to flourish, is for good men to do nothing. .... |
[ARCHIVED THREAD] - Criterion CORE Accuracy Evaluation (Page 2 of 5)
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