Missing notches/holes on barrel nut for ar15

pgb205 · November 27, 2017, 11:08 PM

Bought anderson manufacturing barrel nut kit. Unlike other barrel nuts it's lacking either notches or holes to 'thread' the gas tube into. Before anyone says this I understand that these notches will not keep barrel from rotating etc. But I'd think they would help to keep gas tube stable to some degree? Right now it's just gas tube being attached to the gas block on one end and on the other end it just rattles in the upper receiver gas tube entryway.
I am almost of opinion that maybe I am missing some part or another.

turtlehead · November 27, 2017, 11:37 PM

Sounds right. Does the gas key engage properly (without scraping)?

marine6680 · November 27, 2017, 11:58 PM

Got a picture? I doubt it would be an issue if its just fewer individual notches.

There are several free float handguards that use a barrel nut design that has no notches. The nut is lower profile, and the gas tube clears without needing any cuts for clearance.

They work just fine... And I prefer them, as they make barrel install simple. I simply torque the nut to 50ft/lb and go. I like the torque in the middle of the spec, some torque to min, and others to max.

Either way... no worrying about alignment of the notches.

pgb205 · November 28, 2017, 10:54 AM

that's correct. the barrel nut has no groves or holes of any kind for the gas tube to rest in/on top of. It is a relatively low-profile nut vs the regular A2 version

bfoosh006 · November 28, 2017, 11:03 AM

This is not uncommon.

Bear in mind, you want a certain amount of wiggle in the gas tube... to snug and the gas tube and it gas block can actually mess with your accuracy.

The BCG slamming the "to snug" tube "transmits down to the gas block, and barrel and will not allow consistent / repeatable "locked into battery" performance. You don't want that stuff binding.

If anything ... polish the opening on the BCG gas key, to allow a smooth transition. I use a dremel and a felt cone , with polishing compound... go gently , just enough to smooth it and briefly. BE SURE to thoroughly clean the polishing compound from the gas key
.... you don't want the polishing compound in the BCG parts.

The receiver gas tube hole is GTG for stability.

Also ... make sure your gas block is not mounted in direct contact with the shoulder on the barrel.

Ibmikey · November 29, 2017, 10:29 PM

The tube should be free to flex slightly ( although proper fitting should reduce movement) but not “rattle” anywhere. Did you pin it properly in the gas block? If so there will be no “rattle”.

ed308 · December 15, 2017, 08:55 AM

Plenty of barrel nuts don't have notches. Regarding the rattling of the gas tube, some upper receivers made for a piston AR do have a fitting that slides in gas port opening on the upper receiver. When converting those upper receivers to a DI system, you need to insert a small fitting inside the gas tube opening to reduce the size. If the opening in only large enough for a gas tube, then it's unlikely anything is wrong since AR pistons are usually larger than gas tubes. Like others have said, usually pinning the gas tube to the gas block is all you need to do. I've never had a gas tube rattle in an upper receiver. I would confirm you've properly pinned the gas tube to the gas block.

444 · December 15, 2017, 09:54 AM

I haven't used a barrel nut that had the holes for the gas tube for years. I can't see any reason why anybody still does.

So, I don't think you are missing any parts: that is how it is supposed to be with that barrel nut.

rickyrick · December 15, 2017, 10:20 AM

A lot of people grind the barrel nuts to remove the notches.

Ibmikey · December 16, 2017, 03:41 AM

444, Midwest Industries has a line of hand guards that I really like...they use a barrel nut slightly modified from GI, so that is one reason I still use a nut with notches. I have never had a problem with the notches in all the rifles I have built.

stagpanther · December 18, 2017, 02:54 AM

Avoids having to use two tons of torque in those inevitable builds where the nut is too loose on the previous notch.

November 27, 2017, 11:08 PM	#1
pgb205 Senior Member Join Date: April 11, 2013 Posts: 104	Missing notches/holes on barrel nut for ar15 Bought anderson manufacturing barrel nut kit. Unlike other barrel nuts it's lacking either notches or holes to 'thread' the gas tube into. Before anyone says this I understand that these notches will not keep barrel from rotating etc. But I'd think they would help to keep gas tube stable to some degree? Right now it's just gas tube being attached to the gas block on one end and on the other end it just rattles in the upper receiver gas tube entryway. I am almost of opinion that maybe I am missing some part or another.

December 15, 2017, 09:54 AM	#8
444 Senior Member Join Date: November 20, 2000 Location: Ohio Posts: 3,968	I haven't used a barrel nut that had the holes for the gas tube for years. I can't see any reason why anybody still does. So, I don't think you are missing any parts: that is how it is supposed to be with that barrel nut. __________________ You know the rest. In the books you have read How the British Regulars fired and fled, How the farmers gave them ball for ball, From behind each fence and farmyard wall, Chasing the redcoats down the lane, Then crossing the fields to emerge again Under the trees at the turn of the road, And only pausing to fire and load.

December 18, 2017, 02:54 AM	#11
stagpanther Senior Member Join Date: March 2, 2014 Posts: 11,772	Avoids having to use two tons of torque in those inevitable builds where the nut is too loose on the previous notch. __________________ "Everyone speaks gun."--Robert O'Neill *I am NOT an expert--I do not have any formal experience or certification in firearms use or testing; use any information I post at your own risk!*

November 27, 2017, 11:37 PM	#2
turtlehead Senior Member Join Date: October 20, 2015 Location: Phoenix, AZ Posts: 1,203	Sounds right. Does the gas key engage properly (without scraping)?

November 27, 2017, 11:58 PM	#3
marine6680 Senior Member Join Date: July 24, 2012 Location: Parker, CO Posts: 4,594	Got a picture? I doubt it would be an issue if its just fewer individual notches. There are several free float handguards that use a barrel nut design that has no notches. The nut is lower profile, and the gas tube clears without needing any cuts for clearance. They work just fine... And I prefer them, as they make barrel install simple. I simply torque the nut to 50ft/lb and go. I like the torque in the middle of the spec, some torque to min, and others to max. Either way... no worrying about alignment of the notches.

November 28, 2017, 10:54 AM	#4
pgb205 Senior Member Join Date: April 11, 2013 Posts: 104	that's correct. the barrel nut has no groves or holes of any kind for the gas tube to rest in/on top of. It is a relatively low-profile nut vs the regular A2 version

November 28, 2017, 11:03 AM	#5
bfoosh006 Senior Member Join Date: February 17, 2009 Posts: 1,089	This is not uncommon. Bear in mind, you want a certain amount of wiggle in the gas tube... to snug and the gas tube and it gas block can actually mess with your accuracy. The BCG slamming the "to snug" tube "transmits down to the gas block, and barrel and will not allow consistent / repeatable "locked into battery" performance. You don't want that stuff binding. If anything ... polish the opening on the BCG gas key, to allow a smooth transition. I use a dremel and a felt cone , with polishing compound... go gently , just enough to smooth it and briefly. BE SURE to thoroughly clean the polishing compound from the gas key .... you don't want the polishing compound in the BCG parts. The receiver gas tube hole is GTG for stability. Also ... make sure your gas block is not mounted in direct contact with the shoulder on the barrel.

November 29, 2017, 10:29 PM	#6
Ibmikey Senior Member Join Date: June 1, 2013 Location: Now relocated to Texas Posts: 2,943	The tube should be free to flex slightly ( although proper fitting should reduce movement) but not “rattle” anywhere. Did you pin it properly in the gas block? If so there will be no “rattle”.

December 15, 2017, 08:55 AM	#7
ed308 Senior Member Join Date: November 5, 2016 Location: DFW, TX Posts: 1,147	Plenty of barrel nuts don't have notches. Regarding the rattling of the gas tube, some upper receivers made for a piston AR do have a fitting that slides in gas port opening on the upper receiver. When converting those upper receivers to a DI system, you need to insert a small fitting inside the gas tube opening to reduce the size. If the opening in only large enough for a gas tube, then it's unlikely anything is wrong since AR pistons are usually larger than gas tubes. Like others have said, usually pinning the gas tube to the gas block is all you need to do. I've never had a gas tube rattle in an upper receiver. I would confirm you've properly pinned the gas tube to the gas block.

December 15, 2017, 10:20 AM	#9
rickyrick Senior Member Join Date: March 15, 2010 Posts: 8,236	A lot of people grind the barrel nuts to remove the notches.

December 16, 2017, 03:41 AM	#10
Ibmikey Senior Member Join Date: June 1, 2013 Location: Now relocated to Texas Posts: 2,943	444, Midwest Industries has a line of hand guards that I really like...they use a barrel nut slightly modified from GI, so that is one reason I still use a nut with notches. I have never had a problem with the notches in all the rifles I have built.