View Full Version : Centurion Arms Tabbed Gas Block
Centurion Arms Tabbed Gas Block
https://www.ar15.com/media/mediaFiles/28568/centurion_arms_tabbed_gas_block_022_resi-3029876.jpg
Most of the AR-15 barrels from Centurion Arms now come with a notch that is milled TDC in the shoulder of the gas block journal. This notch aligns with the gas port of the barrel and is intended to interface with the Centurion Arms low-profile “tabbed” gas block.
https://www.ar15.com/media/mediaFiles/28568/centurion_arms_notch_001_resized-3029707.jpg
A precisely machined “tab” in the Centurion Arms gas block dovetails with the notch in the shoulder of the gas block journal to align the gas block with the gas port of the barrel. You can still use a standard 0.750” low profile gas block (or an A2 front sight base) with the Centurion Arms barrels, but you won’t want to, as the tabbed gas block is a work of art.
https://www.ar15.com/media/mediaFiles/28568/centurions_arms_tabbed_gas_block_021_res-3029877.jpg
The notch in the shoulder of the gas block journal has a nominal width of 0.1020” as measured with Mitutoyo digital calipers. The tab on the gas block has a nominal width of 0.1014” as measured with a Mitutoyo micrometer. This creates a transition fit with a clearance of only 0.0006” and there is no rational play with the gas block mounted on the barrel.
https://www.ar15.com/media/mediaFiles/28568/centurion_arms_tabbed_gas_block_on_barre-3029724.jpg
With the tabbed gas block pressed against the shoulder of the gas block journal of the barrel the set-screw threads of the gas block are precisely aligned with the dimples in the 6 o’clock position of the Centurion Arms barrel.
https://www.ar15.com/media/mediaFiles/28568/centurions_arms_barrel_gas_block_journal-3029919.jpg
https://www.ar15.com/media/mediaFiles/28568/centurion_arms_tabbed_gas_block_journal_-3029708.jpg
The Centurion Arms tabbed gas block system makes the process of precisely aligning the gas block with the gas port of the barrel practically foolproof.
https://www.ar15.com/media/mediaFiles/28568/centurion_arms_tabbed_gas_block_borescop-3029740.jpg
The Centurion Arms 0.750” low-profile tabbed gas block weighs 1.1 ounces. As mentioned above, the version that I reviewed is drilled and tapped for use with two set-screws to secure the gas block to the barrel. The US Army Marksmanship Unit discovered years ago that pinning the gas block to the barrel can degrade accuracy.
The bore of the tabbed gas block has a gauged diameter of 0.7495”. When mated with the Centurion Arms barrel that has a nominal gas block journal diameter of 0.7493”, these components have a tight transition fit with only 0.0002” of clearance.
The gas tube channel of the tabbed gas block has a gauged diameter of 0.1801” and when paired with a Centurion Arms mid-length gas tube that has a diameter of 0.1797” at the proximal end, these components create yet another snug transition fit with only 0.0004” of clearance. These tightly toleranced components all contribute to a very efficient gas system and it’s quite refreshing to see a company that produces AR-15 components that hasn’t let their quality control deteriorate over the last few years.
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Stopsign32v
11-16-23, 18:18
That is truly badass
If I'm correct isn't Centurion Arms the creation of an OG Noveske guy?
A simple, but very smart idea that someone should have made industry standard a couple decades ago.
Hammer_Man
11-16-23, 19:21
I’m a huge fan of Centurion Arms gas blocks. They fit perfectly under my KAC URX 3.1 hand guards, in a position that a KAC gas block wouldn’t fit. They had a snug fit requiring a little heat to install (which is perfect IMO), and lined up perfectly with the dimples of my MK12 barrel.
That is truly badass
If I'm correct isn't Centurion Arms the creation of an OG Noveske guy?
No, Centurion Arms was started by Monty LeClair, a Navy Seal who was involved in the MK12 program at NSWC Crane.
The company you’re thinking of is V-Seven.
Stopsign32v
11-16-23, 19:28
Are all barrels/gas blocks of theirs going to be like this?
Hammer_Man
11-16-23, 19:35
Are all barrels/gas blocks of theirs going to be like this?
You can buy their gas block without the tab. Most of, if not all of their barrels come with the cutout for the tab.
Stopsign32v
11-16-23, 19:46
They have already been on my radar for a barrel. I think this might push me over the edge.
A simple, but very smart idea that someone should have made industry standard a couple decades ago.
Jeez, what would PSA customer service have done without all the crooked FSB tickets? ��
Andy
Stopsign32v
11-16-23, 20:01
Jeez, what would PSA customer service have done without all the crooked FSB tickets? ��
Andy
The same thing PSA customer service does now.
Nothing
I don’t understand, the barrel has a dimple directly opposite the gas port so there is no need for any other alignment method.
titsonritz
11-16-23, 20:56
I don’t understand, the barrel has a dimple directly opposite the gas port so there is no need for any other alignment method.
I’m going to guess it was born from the MK-12’s exposed gas block as a method of anti rotation rather than alignment with out pinning which some claim can affect barrel harmonics on a precision gun.
Stopsign32v
11-16-23, 21:02
I don’t understand, the barrel has a dimple directly opposite the gas port so there is no need for any other alignment method.
I mean it's pretty simple to understand the design. The slot is for any type of rotation, not alignment.
the AR-15 Junkie
11-16-23, 23:02
So exactly how long are the set screws? I ask because the CA block I got the screws were only 1/2 as long as a standard GB screws as they machine the bottom of the GB so thin to clear rails. About 2 1/2 threads long is all they were. Didn't look very confidence inspiring to me. Not much metal to go into the dimples.
Centurion Arms Tabbed Gas Block
Most of the AR-15 barrels from Centurion Arms now come with a notch that is milled TDC in the shoulder of the gas block journal. This notch aligns with the gas port of the barrel and is intended to interface with the Centurion Arms low-profile “tabbed” gas block.
A precisely machined “tab” in the Centurion Arms gas block dovetails with the notch in the shoulder of the gas block journal to align the gas block with the gas port of the barrel. You can still use a standard 0.750” low profile gas block (or an A2 front sight base) with the Centurion Arms barrels, but you won’t want to, as the tabbed gas block is a work of art.
The notch in the shoulder of the gas block journal has a nominal width of 0.1020” as measured with Mitutoyo digital calipers. The tab on the gas block has a nominal width of 0.1014” as measured with a Mitutoyo micrometer. This creates a transition fit with a clearance of only 0.0006” and there is no rational play with the gas block mounted on the barrel.
With the tabbed gas block pressed against the shoulder of the gas block journal of the barrel the set-screw threads of the gas block are precisely aligned with the dimples in the 6 o’clock position of the Centurion Arms barrel.
The Centurion Arms tabbed gas block system makes the process of precisely aligning the gas block with the gas port of the barrel practically foolproof.
The Centurion Arms 0.750” low-profile tabbed gas block weighs 1.1 ounces. As mentioned above, the version that I reviewed is drilled and tapped for use with two set-screws to secure the gas block to the barrel. The US Army Marksmanship Unit discovered years ago that pinning the gas block to the barrel can degrade accuracy.
The bore of the tabbed gas block has a gauged diameter of 0.7495”. When mated with the Centurion Arms barrel that has a nominal gas block journal diameter of 0.7493”, these components have a tight transition fit with only 0.0002” of clearance.
The gas tube channel of the tabbed gas block has a gauged diameter of 0.1801” and when paired with a Centurion Arms mid-length gas tube that has a diameter of 0.1797” at the proximal end, these components create yet another snug transition fit with only 0.0004” of clearance. These tightly toleranced components all contribute to a very efficient gas system and it’s quite refreshing to see a company that produces AR-15 components that hasn’t let their quality control deteriorate over the last few years.
…..
Thanks for this review, Molon. Have you reviewed any of their barrels? I'm curious about their medium profile 16" chrome lined barrel.
Dumbing down AR assembly. Not to poop on Centurion at all. But if you can't line up a lo-pro, you are a fukking retard in the first place. There should be no lateral movement when installed, and if that were a possibility, the block would slip forward. And the tab wouldn't help stop that.
So exactly how long are the set screws? I ask because the CA block I got the screws were only 1/2 as long as a standard GB screws as they machine the bottom of the GB so thin to clear rails. About 2 1/2 threads long is all they were. Didn't look very confidence inspiring to me. Not much metal to go into the dimples.
I'm curious about this as well, but I guess it would be a non-issue with the tab + pinning, which maybe is the real reason behind including the tab.
My 14.5 has a Centurion barrel on it. I opted for the tabbed gas block AND had them pin it. IMHO the tab is 50% of the overall solution. The pin is the second half. (Slaps gas block) That's not going anywhere.
Hammer_Man
11-17-23, 10:34
I don’t see what’s not to like about this setup. It doesn’t cost any extra, and the cutout doesn’t prevent you from using a standard gas block of your choice.
I mean it's pretty simple to understand the design. The slot is for any type of rotation, not alignment.
You do not believe that set screws in a dimple will prevent rotation?
the AR-15 Junkie
11-17-23, 13:21
I'm curious about this as well, but I guess it would be a non-issue with the tab + pinning, which maybe is the real reason behind including the tab.
Here is your answer.
https://www.youtube.com/watch?v=fxdDYKPtKes
Here is your answer.
https://www.youtube.com/watch?v=fxdDYKPtKes
Haha! That gave me a good chuckle. I have only used .625" diameter gas blocks with Centurion rails so I was able to use "standard" low-profile gas blocks with the longer set screws. I've picked up some good tips from your other channel, so thanks for that.
the AR-15 Junkie
11-17-23, 14:05
Haha! That gave me a good chuckle. I have only used .625" diameter gas blocks with Centurion rails so I was able to use "standard" low-profile gas blocks with the longer set screws. I've picked up some good tips from your other channel, so thanks for that.
Im not making fun of Monty, but making fun of people who "drop" his name. Like stating; "I talked to Monty last night for 2 hours", "I saw Monty over the weekend, had great conversation". Its like they think by dropping Montys name that automatically gives them some level of credibility lol.
I would not use those gas blocks with those tiny set screws. I wound up drilling and pinning it. Would be helpful if they drilled an undersized pilot hole like the G blocks are made.
Centurion Arms legendary customer service widely known across the industry is because they do to their credit take care of all their 1000's of problems, but there in is the issue. They are only able to have the opportunity to have this level of customer service because, well, they have so many problems. If that makes sense?
If their lower receivers weren't full auto pocket cut so people can "dream and fantasize of making an illegal machine gun", no one would want one as there is nothing really special about them. I once thought there was until I discovered, they are not special. No better than an Anderson. I sold all mine to a LGS.
One question. Did you eat all that Popeyes and drink all that Coke on your own or was that a family pack?
the AR-15 Junkie
11-17-23, 16:53
One question. Did you eat all that Popeyes and drink all that Coke on your own or was that a family pack?
lol, a good lawyer never asks a question he doesn't already know the answer to!
If someone doesn’t like the 1/8” set-screws that come with the tabbed gas block, they could just spend a whopping 58¢ and buy two 5/32” or 3/16” set screws (which is the length often found with low-profile gas blocks). Or, go ahead and use a gas block that doesn't have enough clearance. It's not like I'm receiving royalties for every tabbed gas block sold.
https://i.ibb.co/SszVQzD/centurion-arms-gas-block-with-set-screws-002bl.jpg
The Badger Ordnance TDX gas block is even thinner than the Centurion Arms tabbed gas block and Criterion sells the TDX gas block as an add-on when purchasing their CORE barrels. Has anyone been seeing a lot of failures of the TDX gas block?
https://i.ibb.co/XXcLJsX/centurion-arms-tabbed-gas-block-vs-tdx-gas-block-001-resized.jpg
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1- Im not making fun of Monty, but making fun of people who "drop" his name. Like stating; "I talked to Monty last night for 2 hours", "I saw Monty over the weekend, had great conversation". Its like they think by dropping Montys name that automatically gives them some level of credibility lol.
2- I would not use those gas blocks with those tiny set screws. I wound up drilling and pinning it. Would be helpful if they drilled an undersized pilot hole like the G blocks are made.
3- Centurion Arms legendary customer service widely known across the industry is because they do to their credit take care of all their 1000's of problems, but there in is the issue. They are only able to have the opportunity to have this level of customer service because, well, they have so many problems. If that makes sense?
4- If their lower receivers weren't full auto pocket cut so people can "dream and fantasize of making an illegal machine gun", no one would want one as there is nothing really special about them. I once thought there was until I discovered, they are not special. No better than an Anderson. I sold all mine to a LGS.
1- Who? Don't keep everyone in suspense, post that name so we can all call that person out. Does the individual who made that video post here?
2- Not seeing a set screw failure anywhere, but a hole to pin it wouldn't be a bad idea, though people would want their barrels drilled for that, and its an additional cost as its additional machine time (obviously you already know this part, but others might not). Then again, the flat spot on the block makes it pretty easy for anyone who wants to drill it themselves. Maybe dimple a drill spot, which might be what you were alluding to....
3- Legendary customer service because they take care of all their thousands of problems? No, just no.
4- Nope.
1- Who? Don't keep everyone in suspense, post that name so we can all call that person out. If there is someone talking above their knowledge base, and you feel they are full of it, post that user name so we can confirm or deny that person shouldn't be taken as a legit source of information.
2- Not seeing a set screw failure anywhere, but a hole to pin wouldn't be a bad idea, though people would want their barrels drilled for that, and its an additional cost as its additional machine time (obviously you already know this part, but others might not).
3- Legendary customer service because they take care of all their thousands of problems? No sir, you are incorrect. I'm guessing you are either listening to bogus sources, or you are just playing around and intentionally making up ridiculous numbers for some odd reason. I would love to hear where you gathered your information from so it can be corrected.
4- Nope.
"The other night I was talking with Monty about his 1000's of problems with gas block set screw failures......" :D
Funny but over the weekend I was replacing a handgaurd on a build and used the Centurion set screws, Rocksett them in, and then put roughly 500 rounds of 7.62x39 downrange yesterday (suppressed even) and not a single issue. Imagine that.
I would not feel comfortable running that Badger Ordnance TDX gas block without pinning it at the top.
Does the individual who made that video post here?
I thought the guy in the video is the AR-15 Junkie?
....
I thought the guy in the video is the AR-15 Junkie?
....
Please.... no. Just, no.
Please.... no. Just, no.
I’m thoroughly confused.:confused: the AR-15 Junkie posted this on this website, and then on the next page posted a link to the video.
So exactly how long are the set screws? I ask because the CA block I got the screws were only 1/2 as long as a standard GB screws as they machine the bottom of the GB so thin to clear rails. About 2 1/2 threads long is all they were. Didn't look very confidence inspiring to me. Not much metal to go into the dimples.
On the same day, someone with the user-name OTDR posted this on TOS, along with a link to the same video, within minutes of posting the link to the video on this site.
Originally Posted By OTDR:
So exactly how long are the set screws? I ask because the CA block I got the screws were only 1/2 as long as a standard GB screws as they machine the bottom of the GB so thin to clear rails. About 2 1/2 threads long is all they were. Didn't look very confidence inspiring to me. Not much metal to go into the dimples.
This video explains it all.
http://www.ar15.com/images/2016/icon_video2.png https://www.youtube.com/watch?v=fxdDYKPtKes
....
I thought the guy in the video is the AR-15 Junkie?
AR-15 Junkie usually uses this channel for his video replies: https://www.youtube.com/@ar-15techtipsinunder5minut8
It's the same dude. Shop set up is identical (look at the plaid cloth) in both videos.
1- Who? Don't keep everyone in suspense, post that name so we can all call that person out. Does the individual who made that video post here?
You may already know this, he's simply stroking his boner against Chad from SOTAR. Its literally the only reason he posts his nonsense here, that and to get clicks on his shitty videos.
My vote would be to swing the BAN HAMMER on this idiot. But alas, I will at least keep him on my IL and hope good folks don't quote his nonsense. :)
Hammer_Man
11-20-23, 17:26
You may already know this, he's simply stroking his boner against Chad from SOTAR. Its literally the only reason he posts his nonsense here, that and to get clicks on his shitty videos.
My vote would be to swing the BAN HAMMER on this idiot. But alas, I will at least keep him on my IL and hope good folks don't quote his nonsense. :)
My take is that he’s “Okie light”
My take is that he’s “Okie light”
Careful, he might show you his lizard. https://www.youtube.com/watch?v=aGYaBBWGP9A
titsonritz
11-21-23, 01:15
I thought the guy in the video is the AR-15 Junkie?
....
My take is that he’s “Okie light”
You are both correct
You are both correct
:D
I kinda miss Okie. Getting down "innagrass" just isn't the same without him here.
:D
I kinda miss Okie. Getting down "innagrass" just isn't the same without him here.
Did Okie get banned or just disappear? He, at least, had a likeable personality.
Did Okie get banned or just disappear? He, at least, had a likeable personality.
Last post was in January. Doesn't look like he was banned. Probably just tired of getting ridden.
Thanks for this review, Molon. Have you reviewed any of their barrels? I'm curious about their medium profile 16" chrome lined barrel.
I had a Centurion Arms "light-weight" CHF barrel, but never did a formal accuracy evaluation of it. For starters, it's not a light-weight barrel. For decades the de facto standard for what constitutes a 16” light-weight AR-15 barrel, has been the barrel found on the Colt 6520/6720. That barrel weights 1 pound, 6 ounces.
https://www.ar15.com/media/mediaFiles/28568/colt_6520_barrel_001-2255250.jpg
The Centurion “light-weight” barrel is pretty much a government profile barrel. The one I owned weighed 1 pound, 10.5 ounces; so more than a quarter of a pound heavier than an actual light-weight barrel.
16 LW Centurion barrel . . .
https://www.ar15.com/media/mediaFiles/28568/centurion_barrl_21-2255243.jpg
The 10-shot group pictured below is just a rough-zero group at 25 yards. The group has an extreme spread of 1.37 MOA.
https://www.ar15.com/media/mediaFiles/28568/centurion_midlength-2255244.jpg
I'll be doing a full evaluation of the Centurion Arms Enhanced SOCOM barrel in the future . . .
https://i.ibb.co/3Tkxkv7/centurion-arms-14-5-enhanced-SOCOM-024.jpg
https://i.ibb.co/YBtFyts/ca-enhanced-socom-weight-on-scale-001.jpg
.....
I had a Centurion Arms "light-weight" CHF barrel, but never did a formal accuracy evaluation of it. For starters, it's not a light-weight barrel. For decades the de facto standard for what constitutes a 16” light-weight AR-15 barrel, has been the barrel found on the Colt 6520/6720. That barrel weights 1 pound, 6 ounces.
https://www.ar15.com/media/mediaFiles/28568/colt_6520_barrel_001-2255250.jpg
The Centurion “light-weight” barrel is pretty much a government profile barrel. The one I owned weighed 1 pound, 10.5 ounces; so more than a quarter of a pound heavier than an actual light-weight barrel.
16 LW Centurion barrel . . .
https://www.ar15.com/media/mediaFiles/28568/centurion_barrl_21-2255243.jpg
The 10-shot group pictured below is just a rough-zero group at 25 yards. The group has an extreme spread of 1.37 MOA.
https://www.ar15.com/media/mediaFiles/28568/centurion_midlength-2255244.jpg
I'll be doing a full evaluation of the Centurion Arms Enhanced SOCOM barrel in the future . . .
https://i.ibb.co/3Tkxkv7/centurion-arms-14-5-enhanced-SOCOM-024.jpg
https://i.ibb.co/YBtFyts/ca-enhanced-socom-weight-on-scale-001.jpg
.....Sounds good all the way around. Thank you.
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