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Posted: 7/13/2016 10:26:37 PM EDT
[Last Edit: Molon]
AR-15 Gas Ports: Krieger versus Ballistic Advantage
The first bore-scope view shown below shows the gas port on a new Krieger AR-15 barrel. Note the absence of any burrs at the port and the beveled surface leading into the gas port. Also note the whole gas port is positioned in a groove of the barrel; no part of the gas port cuts into a land. Attached File The next bore-scope view shows the gas port (at 6 o’clock) on a new Ballistic Advantage "Modern Series" AR-15 barrel, taken from a different angle than that of the Krieger barrel to show the large burr at the gas port. I wasn’t able to remove this burr with a cleaning rod, so it will have to be shot out. Also note that part of the gas port cuts into one of the lands. Attached File This illustrates just one small example of the expertise and time that you’re paying for when buying a top-tier AR-15 barrel. |
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All that is necessary for Trolls to flourish, is for good men to do nothing.
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From my discussion with krieger a while ago, they do not finish their AR-15 barrels like most.
They actually drill the gas port FIRST, to ensure it is in a groove. This is a technique carried over from making M14 barrels. The fact that they put the entire port into the groove is also why they will not sell finished semi-auto barrels (M14 or AR platform) with 5R rifling. You can still get one if you buy a 5R blank, but someone else will have to drill the port. After drilling the port, they then time the barrel extension. If you look on your barrel, there should be a mark just in front of the extension that indicates the 12 o'clock position. Probably there to help with timing. |
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Originally Posted By Lennyo3034:
From my discussion with krieger a while ago, they do not finish their AR-15 barrels like most. They actually drill the gas port FIRST, to ensure it is in a groove. This is a technique carried over from making M14 barrels. The fact that they put the entire port into the groove is also why they will not sell finished semi-auto barrels (M14 or AR platform) with 5R rifling. You can still get one if you buy a 5R blank, but someone else will have to drill the port. After drilling the port, they then time the barrel extension. If you look on your barrel, there should be a mark just in front of the extension that indicates the 12 o'clock position. Probably there to help with timing. View Quote This is correct. |
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"If you're gonna be a bear, be a grizzly."
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All that is necessary for Trolls to flourish, is for good men to do nothing.
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The attention to detail Krieger applies is extraordinary. That BA barrel is probably not only "just fine," but will probably shoot really well. But Krieger's keeping the entire gas port in a groove means that it has nothing getting in the way of the bullet's contact with the rifling, and probably gets a tiny bit better seal when the bullet passes the port.
I'm amazed at how they could actually bevel the bore side of the gas port! Molon, what bore scope do you use? |
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"--you can't conquer a free man; the most you can do is kill him."
Heinlein NRA Life Member Glock Certified Armorer Certified AR15 Armorer Certified M1911 Armorer |
Originally Posted By GHPorter:
The attention to detail Krieger applies is extraordinary. That BA barrel is probably not only "just fine," but will probably shoot really well. But Krieger's keeping the entire gas port in a groove means that it has nothing getting in the way of the bullet's contact with the rifling, and probably gets a tiny bit better seal when the bullet passes the port. I'm amazed at how they could actually bevel the bore side of the gas port! Molon, what bore scope do you use? View Quote See the link below. The camera snap-shots that I post do no justice to the quality of this instrument. http://www.midwayusa.com/product/303817/hawkeye-deluxe-borescope-17-slim-focusing-kit ... |
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All that is necessary for Trolls to flourish, is for good men to do nothing.
In God We Trust. Everyone else must post data. |
Originally Posted By Molon:
See the link below. The camera snap-shots that I post do no justice to the quality of this instrument. http://www.midwayusa.com/product/303817/hawkeye-deluxe-borescope-17-slim-focusing-kit ... View Quote Very nice! Thanks! |
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"--you can't conquer a free man; the most you can do is kill him."
Heinlein NRA Life Member Glock Certified Armorer Certified AR15 Armorer Certified M1911 Armorer |
Not disputing any quality difference but it should he mentioned there's a 100% price difference between your samples and a not yet measured performance difference (that I'm aware of...not a regular. Might have missed one of your many excellent posts) ;-) I'm very positive Lilja does better. Love to own one, and the right ammo for it. Currently I'm OK with BA and quality boxed ammo.
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That must be part of why my 6mmAR shoots 3/4 inch 10 shot groups at 100 yards.
Krieger makes good barrels. |
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Originally Posted By GHPorter:
The attention to detail Krieger applies is extraordinary. That BA barrel is probably not only "just fine," but will probably shoot really well. But Krieger's keeping the entire gas port in a groove means that it has nothing getting in the way of the bullet's contact with the rifling, and probably gets a tiny bit better seal when the bullet passes the port. I'm amazed at how they could actually bevel the bore side of the gas port! Molon, what bore scope do you use? View Quote That's actually not that hard. Anyone doing production drilling of gas ports can do it. They choose not to. The tooling is available to anyone. Deburring/chamferring the inside of small radial holes is a common necessity in a number of machining industries. |
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Originally Posted By ROMAD-556: . . . a not yet measured performance difference . . . View Quote The accuracy/precision produced by 5.56mm/223 Remington Krieger AR-15 barrels has been well documented. All of the 10-shot groups pictured below were fired from AR-15s that have 5.56mm/223 Remington Krieger AR-15 barrels. Attached File Attached File Attached File Attached File .... |
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All that is necessary for Trolls to flourish, is for good men to do nothing.
In God We Trust. Everyone else must post data. |
Originally Posted By Kuraki:
That's actually not that hard. Anyone doing production drilling of gas ports can do it. They choose not to. The tooling is available to anyone. Deburring/chamferring the inside of small radial holes is a common necessity in a number of machining industries. View Quote View All Quotes View All Quotes Originally Posted By Kuraki:
Originally Posted By GHPorter:
I'm amazed at how they could actually bevel the bore side of the gas port! That's actually not that hard. Anyone doing production drilling of gas ports can do it. They choose not to. The tooling is available to anyone. Deburring/chamferring the inside of small radial holes is a common necessity in a number of machining industries. Without derailing this too much, how does one bevel the far side of a hole bored through a barrel? I can't picture how to do it... |
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"--you can't conquer a free man; the most you can do is kill him."
Heinlein NRA Life Member Glock Certified Armorer Certified AR15 Armorer Certified M1911 Armorer |
Thank You for sharing !!!
It constantly amazes me how much barrel making can be an art, rather then just a mechanical process. I will enjoy seeing where this thread goes. |
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*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
JAFOM |
Originally Posted By Molon:
Then you should have no difficulty posting pics of 10-shot groups, fired from AR-15s that have 5.56mm/223 Remington Lilja barrels, that are "better" than the groups I posted. View Quote I wish! I cant afford a Lilja, that's just stuff of dreams for me. I wasn't challenging you or your groups I only was saying I have no doubt that the Lilja barrel is a better performer than the Ballistic Advantage barrel. Plus there's no way I'm posting better groups than you pretty much ever in my life - I know I am not that good of a shot. |
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All that is necessary for Trolls to flourish, is for good men to do nothing.
In God We Trust. Everyone else must post data. |
Molon,
Thank you once again for your time and effort in putting out this info. Looking forward to seeing the accuracy results of the BA barrel. |
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interesting thread. I have been wishing the gun world had a thing like UL. I can find out which products are different thanks to the box but in the gun world some barrel makers won't even tell you if the barrel is chrome lined.
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"USA USA USA"
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I just read Molon's same thread on TOS, and the responses. What a shitshow. Isn't it supposed to be the other way around?
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Im glad you decided to bring it up here it is very helpful.
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"USA USA USA"
-winners everywhere. |
Originally Posted By Lennyo3034:
I just read Molon's same thread on TOS, and the responses. What a shitshow. Isn't it supposed to be the other way around? View Quote I had to go see. WOW! What a bunch of crap. Molon, one question on "the other site" was "what effect does gas port placement have on accuracy"? Just from looking at the photo I can hazard a few guesses. What is your take? |
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"--you can't conquer a free man; the most you can do is kill him."
Heinlein NRA Life Member Glock Certified Armorer Certified AR15 Armorer Certified M1911 Armorer |
Originally Posted By GHPorter: I had to go see. WOW! What a bunch of crap. Molon, one question on "the other site" was "what effect does gas port placement have on accuracy"? Just from looking at the photo I can hazard a few guesses. What is your take? View Quote View All Quotes View All Quotes Originally Posted By GHPorter: Originally Posted By Lennyo3034: I just read Molon's same thread on TOS, and the responses. What a shitshow. Isn't it supposed to be the other way around? I had to go see. WOW! What a bunch of crap. Molon, one question on "the other site" was "what effect does gas port placement have on accuracy"? Just from looking at the photo I can hazard a few guesses. What is your take? |
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FBHO
Teener Krew 4 Lyfe "Technique isn't something that can be taught. It's something you find on your own." - Bunta Fujiwara |
Originally Posted By HighpowerRifleBrony:
http://benchrest.com/showthread.php?66814-Drilling-gas-Port-AR15&p=554782#post554782 View Quote View All Quotes View All Quotes Originally Posted By HighpowerRifleBrony:
Originally Posted By GHPorter:
Originally Posted By Lennyo3034:
I just read Molon's same thread on TOS, and the responses. What a shitshow. Isn't it supposed to be the other way around? I had to go see. WOW! What a bunch of crap. Molon, one question on "the other site" was "what effect does gas port placement have on accuracy"? Just from looking at the photo I can hazard a few guesses. What is your take? Pffft Robert Whitley. What does he know? |
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"Peace has cost you your strength and victory has defeated you!"
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Molon, thanks again for another great report! arfcom needs more posters like you. its obvious Krieger has set the standard when it comes to barrel making! |
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living well is the best revenge!
ETERNAL R & R my brothers CPT Ritz, SSG Epps, SSG Ortiz, LTC Rennie Cory Jr... C co 2/325th ABN INF 82ND ABN. 83-86 |
Originally Posted By GHPorter:
I had to go see. WOW! What a bunch of crap. Molon, one question on "the other site" was "what effect does gas port placement have on accuracy"? Just from looking at the photo I can hazard a few guesses. What is your take? View Quote View All Quotes View All Quotes Originally Posted By GHPorter:
Originally Posted By Lennyo3034:
I just read Molon's same thread on TOS, and the responses. What a shitshow. Isn't it supposed to be the other way around? I had to go see. WOW! What a bunch of crap. Molon, one question on "the other site" was "what effect does gas port placement have on accuracy"? Just from looking at the photo I can hazard a few guesses. What is your take? You should contact Krieger and have them explain it. ... |
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All that is necessary for Trolls to flourish, is for good men to do nothing.
In God We Trust. Everyone else must post data. |
Aircraft deburring tools come in handy when removing possible stress risers and burrs from blind holes . They are also simple to make . Just imagine an aircraft rivet length selector with a sharp edge .
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Originally Posted By Molon:
You should contact Krieger and have them explain it. ... View Quote View All Quotes View All Quotes Originally Posted By Molon:
Originally Posted By GHPorter:
Originally Posted By Lennyo3034:
I just read Molon's same thread on TOS, and the responses. What a shitshow. Isn't it supposed to be the other way around? I had to go see. WOW! What a bunch of crap. Molon, one question on "the other site" was "what effect does gas port placement have on accuracy"? Just from looking at the photo I can hazard a few guesses. What is your take? You should contact Krieger and have them explain it. ... I think I will. Especially after reading the thread HighpowerRifleBrony linked to! Those folks slung the poo ever so politely (mostly), and it came down to "my experience" and "it ain't handed down from God that you gotta put it in a groove." Wow! |
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"--you can't conquer a free man; the most you can do is kill him."
Heinlein NRA Life Member Glock Certified Armorer Certified AR15 Armorer Certified M1911 Armorer |
Originally Posted By GHPorter:
Without derailing this too much, how does one bevel the far side of a hole bored through a barrel? I can't picture how to do it... View Quote View All Quotes View All Quotes Originally Posted By GHPorter:
Originally Posted By Kuraki:
Originally Posted By GHPorter:
I'm amazed at how they could actually bevel the bore side of the gas port! That's actually not that hard. Anyone doing production drilling of gas ports can do it. They choose not to. The tooling is available to anyone. Deburring/chamferring the inside of small radial holes is a common necessity in a number of machining industries. Without derailing this too much, how does one bevel the far side of a hole bored through a barrel? I can't picture how to do it... Several options here. http://cogsdill.com/toolprogram/deburring-tools/ |
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Tough times breed strong people, Strong people create good times, Good times breed weak people, Weak people create tough times
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Originally Posted By Molon:
The next bore-scope view shows the gas port (at 6 o’clock) on a new Ballistic Advantage "Modern Series" AR-15 barrel, taken from a different angle than that of the Krieger barrel to show the large burr at the gas port. I wasn’t able to remove this burr with a cleaning rod, so it will have to be shot out. View Quote Thank you. |
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Originally Posted By Badger52:
Re-reading this nice thread (without getting borescope tool envy) I was wondering if this is typically a process where, pretty quickly, the gun suddenly "comes around" or something that is gradually noticed over hundreds or thousands of rounds? Thank you. View Quote You could easily feel it snagging the cleaning pellets.... and was kind of a let down, considering the rest of the barrel, chamber, leade and crown looked very good. It now has about 300rds down the barrel... I need to look at it again with the Lyman bore scope. Accuracy with the burr , was consistent.. but the precision was lacking. .. IMHO. That said, all 10rd groups were still quite respectable and a 20rd group of S&B FMJ was very good...but I am sure the burr ( along with a poor fitting upper and lower,... since fixed ) did nothing to help precision. The burr wouldn't allow any stellar , take you breath away groups... most rds would group well, but no real, all in one hole... one shot after the other. I wish I could have captured one of the S&B bullets... just to inspect the damage to the bullet from the burr. I won't be able to shoot it until next weekend. I haven't had a chance to clean the barrel , since I was curious about the general fouling and copper fouling the barrel was producing.. and want to look that with the Bore scope. I will try to run a felt pellet down the bore and the take a bore cam photo of the burr after the first of many 1gal Ziploc bags worth of a spent cases. |
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*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
JAFOM.... Just another fat old man. |
Some years back I stopped by the Krieger booth at Shot Show and chatted with them. I told them how impressed I was with the upper they put together for me with their barrel. I asked how in the heck do you get the port in the groove?
He said, "math". |
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Got a gun, fact I got two
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Originally Posted By glorifiedG:
Some years back I stopped by the Krieger booth at Shot Show and chatted with them. I told them how impressed I was with the upper they put together for me with their barrel. I asked how in the heck do you get the port in the groove? He said, "math". View Quote |
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Originally Posted By bfoosh06:
I won't be able to shoot it until next weekend. I haven't had a chance to clean the barrel , since I was curious about the general fouling and copper fouling the barrel was producing.. and want to look that with the Bore scope. I will try to run a felt pellet down the bore and the take a bore cam photo of the burr after the first of many 1gal Ziploc bags worth of a spent cases. View Quote |
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*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
JAFOM.... Just another fat old man. |
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Was that unfired and cleaned?
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Distinguished Rifleman #2223
#FreeBradders "Technique isn't something that can be taught. It's something you find on your own." - Bunta Fujiwara |
Originally Posted By nihilsum:
If you had a port bur, it should have burned away relatively quickly. Mine was gone in the first 50-100 rounds. This is a .223 wylde BA match barrel when new: https://i.imgur.com/oZVAcvJ.jpg https://i.imgur.com/2tXf5Kk.jpg https://i.imgur.com/clSn6Tu.jpg It shoots well now, but produced a lot of copper fouling while breaking in. View Quote And I sure hope it is gone... the rest of the barrel looked very nice and crisp. Even the crown , chamber, and throat / leade looked great. The amount of felt yanked from the cleaning pellets was substantial... enough that if it wasn't going to get "burned out" It probably would have been a bizarre " why isn't my gas gun functioning right" thread. Now I am going to have to look at it tonight. |
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*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
JAFOM.... Just another fat old man. |
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Those are great barrels and your photo essay shows exactly what you are paying for. CNC machining does well, but the last 2% is in the heart of the craftsman.
I can tell the difference at 100 yards, but I don't have near enough range time over varied environments to where it makes a difference for me at 600-1000 yds where wind calls put just about every other variable down into the noise floor. Those barrels are worth every penny if you've already spent ten times as much in serious ammo expenditure or compete at a high enough level where paying to remove doubt about equipment is more about the shooter than the hardware. Always enjoy your posts objectivity and concise delivery. ETA: I just realized this is a necro-thread. Is Molon still around? |
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Did you bring this to the attention of BA? What did they say? I'm wondering if their performance Handon and SS Hanson barrels receive a little more attention to detail.
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FWIW... I just received my Krieger 22" .936GB 6.5CM... I now have more stimulus to review the burr in the BA / DSG Arms 22" . 936GB 6.5CM and measure both GP sizes.
The BA I fired about 300+ ( ? ) rds through of various ammos.... so the burr should be gone. and it should be "smoothed" out. |
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*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
JAFOM.... Just another fat old man. |
Originally Posted By KalmanPhilter:
Those are great barrels and your photo essay shows exactly what you are paying for. CNC machining does well, but the last 2% is in the heart of the craftsman. I can tell the difference at 100 yards, but I don't have near enough range time over varied environments to where it makes a difference for me at 600-1000 yds where wind calls put just about every other variable down into the noise floor. Those barrels are worth every penny if you've already spent ten times as much in serious ammo expenditure or compete at a high enough level where paying to remove doubt about equipment is more about the shooter than the hardware. Always enjoy your posts objectivity and concise delivery. ETA: I just realized this is a necro-thread. Is Molon still around? View Quote |
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NO BRAINER...........KREIGER. ITS LIKE A VW TO A CADDY
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poor vision sorry, no spaming from me................
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Originally Posted By Blowout:
After reading this thread, had to check the gas port location on a BA 16" premium barrel I recently assembled into a carbine. Crappy Chinese 5mm camera scope makes it look like one of those space ship photos... but you can see the port (space ship) is in a groove and not centered and just touching a land. The camera doesn't have a focus, but for under $10 its better than nothing. I took a picture with my cell phone and that didn't help either. https://farm8.staticflickr.com/7841/32391860027_54f89f0a83_c.jpg View Quote |
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All that is necessary for Trolls to flourish, is for good men to do nothing.
In God We Trust. Everyone else must post data. |
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"Technique isn't something that can be taught. It's something you find on your own." - Bunta Fujiwara
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All that is necessary for Trolls to flourish, is for good men to do nothing.
In God We Trust. Everyone else must post data. |
stickman used to post cool pics. thanks Molon!
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"Over the years, it has become increasingly difficult to tell the difference between skilled trolls versus fucking morons." DK-Prof
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