AR 15 BARREL & BBL. EXTENSION QUESTIONS - The Firearms Forum

JOHNNYRINGO · 12-21-2008, 07:09 AM

Bought "new" barrel from Sarco (ar300). Barrel came with gas hole drilled, front sight removed, and no bbl. extension installed. Bbl. extension had been removed. Also ordered bbl. extension which came with extension mounted on a piece of what looks like old a1 bbl. chamber end with about 8" of old bbl. tried to remove extension and could not get it to move. I have proper extension wrench. Talked to "Earl" at Sarco and he suggested heating ext. with torch. Still couldn't remove. Ordered new extension and found it would not time out properly so that pin and gas hole lined up. Ordered another brand of extension and it almost times correctly. Suspect that during assembly of new bbl., bbl. extension is installed first and then gas hole is drilled. Short of Drilling new gas hole and filling grooves under bbl., what should I do? Barrel was $35. and extension @ $20. Hate to junk it.

Mark · 12-21-2008, 08:02 AM

Barrel extensions are produced with no regard for timing. If you had 10 barrel extensions, only by luck would two be the same.
Likewise with AR-15 barrels. These are produced with no regard to timing.

A common practice is to locktite barrel extensions on. The heat should loosen the locktite.

You are correct. The way these are fit is to install the barrel extension, then align everything to the pin in the extension. The gas port would be drilled after the extension is installed.
The only thing I can think of would be for a manufacturer to let you keep trying barrel extensions until one lines up. Good luck on this. Otherwise, by finding an extension that would be 90 degrees off, the side of the gas block should cover the port you have now. Then you drill a new port in the correct location. This is not a good fix.

It sounds like you are dealing with someone that has junk to get rid of. Its a good thing you're not in that deep.
Mark

JOHNNYRINGO · 12-21-2008, 08:35 AM

Mark,
Thanks for the quick reply and confirmation about mfg. method of aligning gas hole. I originally bought barrel with the intention of making a dedicated .22 l.r. upper using my conversion kit. It would not matter about the gas hole since the action is "blow back". The barrel appears to have never been shot and I don't know why they were sold to Sarco. I also see what appears to be to be the same bbl. offered by Numrich at twice the price. I have a front gas block with picatinny rails that is held on with set screws which would eliminate the need to fill the cuts for the taper pins that are cut into the bbl. I would only need to fill the gas hole and line up and drill another to fit the new gas block.
Also, the hint that I would buy "JUNK" hurts my tender feelings !!! JUNQUE, yes. JUNK, no way!! I am a die hard tinkerer and see the beauty and majesty in what can be created from others cast-offs. Besides, I have a friend that I will get to shoot this thing if I can master the gas hole problem.

Mark · 12-22-2008, 07:03 PM

I understand buying a project. It does sound like you had to buy more than you wanted attempting to get things to work. It also sounds like "Earl" didn't do you any favors. Why did he sell you a stub barrel when you only needed an extension?

I didn't mean to hurt your feelings. It doesn't sound like you originally wanted a .22rf upper, the original post mentions wanting to align the gas port. Why worry about the port on a blow-back action?
I'm sorry I responded.
Mark

12-21-2008, 07:09 AM	#1
JOHNNYRINGO Member Join Date: Dec 2008 Posts: 2	AR 15 BARREL & BBL. EXTENSION QUESTIONS Bought "new" barrel from Sarco (ar300). Barrel came with gas hole drilled, front sight removed, and no bbl. extension installed. Bbl. extension had been removed. Also ordered bbl. extension which came with extension mounted on a piece of what looks like old a1 bbl. chamber end with about 8" of old bbl. tried to remove extension and could not get it to move. I have proper extension wrench. Talked to "Earl" at Sarco and he suggested heating ext. with torch. Still couldn't remove. Ordered new extension and found it would not time out properly so that pin and gas hole lined up. Ordered another brand of extension and it almost times correctly. Suspect that during assembly of new bbl., bbl. extension is installed first and then gas hole is drilled. Short of Drilling new gas hole and filling grooves under bbl., what should I do? Barrel was $35. and extension @ $20. Hate to junk it. -->

12-21-2008, 08:02 AM	#2
Mark V.I.P. Member Join Date: Jul 2006 Posts: 314	Re: AR 15 BARREL & BBL. EXTENSION QUESTIONS Barrel extensions are produced with no regard for timing. If you had 10 barrel extensions, only by luck would two be the same. Likewise with AR-15 barrels. These are produced with no regard to timing. A common practice is to locktite barrel extensions on. The heat should loosen the locktite. You are correct. The way these are fit is to install the barrel extension, then align everything to the pin in the extension. The gas port would be drilled after the extension is installed. The only thing I can think of would be for a manufacturer to let you keep trying barrel extensions until one lines up. Good luck on this. Otherwise, by finding an extension that would be 90 degrees off, the side of the gas block should cover the port you have now. Then you drill a new port in the correct location. This is not a good fix. It sounds like you are dealing with someone that has junk to get rid of. Its a good thing you're not in that deep. Mark

12-21-2008, 08:35 AM	#3
JOHNNYRINGO Member Join Date: Dec 2008 Posts: 2	Re: AR 15 BARREL & BBL. EXTENSION QUESTIONS Mark, Thanks for the quick reply and confirmation about mfg. method of aligning gas hole. I originally bought barrel with the intention of making a dedicated .22 l.r. upper using my conversion kit. It would not matter about the gas hole since the action is "blow back". The barrel appears to have never been shot and I don't know why they were sold to Sarco. I also see what appears to be to be the same bbl. offered by Numrich at twice the price. I have a front gas block with picatinny rails that is held on with set screws which would eliminate the need to fill the cuts for the taper pins that are cut into the bbl. I would only need to fill the gas hole and line up and drill another to fit the new gas block. Also, the hint that I would buy "JUNK" hurts my tender feelings !!! JUNQUE, yes. JUNK, no way!! I am a die hard tinkerer and see the beauty and majesty in what can be created from others cast-offs. Besides, I have a friend that I will get to shoot this thing if I can master the gas hole problem. Last edited by JOHNNYRINGO; 12-21-2008 at 08:37 AM..

12-22-2008, 07:03 PM	#4
Mark V.I.P. Member Join Date: Jul 2006 Posts: 314	Re: AR 15 BARREL & BBL. EXTENSION QUESTIONS I understand buying a project. It does sound like you had to buy more than you wanted attempting to get things to work. It also sounds like "Earl" didn't do you any favors. Why did he sell you a stub barrel when you only needed an extension? I didn't mean to hurt your feelings. It doesn't sound like you originally wanted a .22rf upper, the original post mentions wanting to align the gas port. Why worry about the port on a blow-back action? I'm sorry I responded. Mark