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9/12/2015 3:29:21 PM EDT
I'm getting ready to start my first build and have a question. I have watched some you tube videos of people installing AR15 barrels ,some use grease, some use nickel anti seize and some use nothing. My question is do you put grease on the barrel extension prior to installing into the upper to prevent corrosion or is it supposed to be left dry.
Thanks,bcbsr
9/12/2015 4:11:39 PM EDT
[#1]

Quoted:


I'm getting ready to start my first build and have a question. I have watched some you tube videos of people installing AR15 barrels ,some use grease, some use nickel anti seize and some use nothing. My question is do you put grease on the barrel extension prior to installing into the upper to prevent corrosion or is it supposed to be left dry.

Thanks,bcbsr
View Quote
I always use Aeroshell on the barrel extension and receiver threads.

 
9/12/2015 4:18:16 PM EDT
[#2]
Upper receiver - to - barrel nut threads do need lubricant.
9/12/2015 4:38:43 PM EDT
[#3]
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Quoted:
I always use Aeroshell on the barrel extension and receiver threads.  
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Quoted:
Quoted:
I'm getting ready to start my first build and have a question. I have watched some you tube videos of people installing AR15 barrels ,some use grease, some use nickel anti seize and some use nothing. My question is do you put grease on the barrel extension prior to installing into the upper to prevent corrosion or is it supposed to be left dry.
Thanks,bcbsr
I always use Aeroshell on the barrel extension and receiver threads.  



TRUE of Aeroshell...
It is SO east to align the gas tube cove !!
And easier to torque the piss, out of one that went past your cove.  
9/12/2015 5:06:13 PM EDT
[#4]
Quoted:
I'm getting ready to start my first build and have a question. I have watched some you tube videos of people installing AR15 barrels ,some use grease, some use nickel anti seize and some use nothing. My question is do you put grease on the barrel extension prior to installing into the upper to prevent corrosion or is it supposed to be left dry.
Thanks,bcbsr
View Quote

The barrel extension won't corrode, and you don't need to put any grease on it.  If the fit between your barrel and your upper is kinda snug, you may want a little grease on the barrel extension, but it's not needed.  The barrel nut threads and the upper's threads need a decent grease to allow them to settle together well and to smooth out the nut's movement when you torque the nut.  I've never found it easy to over-torque a barrel nut...  I use AeroShell 33MS.  You can find it in small quantities all over the place (check out Amazon, for example).

The technique that works best for me is to apply the grease to the upper's threads, insert the barrel and hand-tighten the barrel nut.  Starting with the nut hand tight, use an appropriate barrel nut wrench to torque the nut to 30 foot/lbs, then back it off.  Retorque to 30 ft/lb and back off.  Repeat once more.  Now torque to at least 30 ft/lb and line up the next notch on the barrel nut (without going above 80 ft/lb).
9/12/2015 5:27:41 PM EDT
[#5]
Thanks for the tips guys , very good information. I'll get some Aeroshell 33MS
9/12/2015 8:10:11 PM EDT
[#6]

Quote History
Quoted:
TRUE of Aeroshell...

It is SO east to align the gas tube cove !!

And easier to torque the piss, out of one that went past your cove.  
View Quote View All Quotes
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Quoted:



Quoted:


Quoted:

I'm getting ready to start my first build and have a question. I have watched some you tube videos of people installing AR15 barrels ,some use grease, some use nickel anti seize and some use nothing. My question is do you put grease on the barrel extension prior to installing into the upper to prevent corrosion or is it supposed to be left dry.

Thanks,bcbsr
I always use Aeroshell on the barrel extension and receiver threads.  






TRUE of Aeroshell...

It is SO east to align the gas tube cove !!

And easier to torque the piss, out of one that went past your cove.  
In English please

 
9/12/2015 8:11:03 PM EDT
[#7]

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Quoted:


Thanks for the tips guys , very good information. I'll get some Aeroshell 33MS
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It can be found rather cheaply if you want small quantities.

 
9/12/2015 10:07:25 PM EDT
[#8]
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Quoted:
The technique that works best for me is to apply the grease to the upper's threads, insert the barrel and hand-tighten the barrel nut.  Starting with the nut hand tight, use an appropriate barrel nut wrench to torque the nut to 30 foot/lbs, then back it off.  Retorque to 30 ft/lb and back off.  Repeat once more.  Now torque to at least 30 ft/lb and line up the next notch on the barrel nut (without going above 80 ft/lb).
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This is the standard method that everyone recommends. I've used it numerous times, however it doesn't always work.  
I just built a new upper this week, and I could not succeed.  30 lbs would leave 1/3 of a tooth in the way.  40/50/60/70/80 lbs was not enough to clear it.
I tried torquing and re-torquing at least a dozen times if not more.

I didn't want to lap the upper face because it's not clear that's a good thing to do in general.
So I ordered some 0.001"  barrel shims (3 for $10 shipped, from Bison Armory).  Popped one shim on and presto everything was good with just 40 libs.
IMHO this is the right solution if you don't succeed with 50-60 lbs.



9/13/2015 12:01:04 AM EDT
[#9]
Quote History
Quoted:

This is the standard method that everyone recommends. I've used it numerous times, however it doesn't always work.  
I just built a new upper this week, and I could not succeed.  30 lbs would leave 1/3 of a tooth in the way.  40/50/60/70/80 lbs was not enough to clear it.
I tried torquing and re-torquing at least a dozen times if not more.

I didn't want to lap the upper face because it's not clear that's a good thing to do in general.
So I ordered some 0.001"  barrel shims (3 for $10 shipped, from Bison Armory).  Popped one shim on and presto everything was good with just 40 libs.
IMHO this is the right solution if you don't succeed with 50-60 lbs.



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Quoted:
Quoted:
The technique that works best for me is to apply the grease to the upper's threads, insert the barrel and hand-tighten the barrel nut.  Starting with the nut hand tight, use an appropriate barrel nut wrench to torque the nut to 30 foot/lbs, then back it off.  Retorque to 30 ft/lb and back off.  Repeat once more.  Now torque to at least 30 ft/lb and line up the next notch on the barrel nut (without going above 80 ft/lb).

This is the standard method that everyone recommends. I've used it numerous times, however it doesn't always work.  
I just built a new upper this week, and I could not succeed.  30 lbs would leave 1/3 of a tooth in the way.  40/50/60/70/80 lbs was not enough to clear it.
I tried torquing and re-torquing at least a dozen times if not more.

I didn't want to lap the upper face because it's not clear that's a good thing to do in general.
So I ordered some 0.001"  barrel shims (3 for $10 shipped, from Bison Armory).  Popped one shim on and presto everything was good with just 40 libs.
IMHO this is the right solution if you don't succeed with 50-60 lbs.





Or just get a free float hand guard that doesn't need to be timed like BCM KMR or Geissele if you prefer M-Lok and call it a day...... Still need to use Aeroshell grease though.
9/13/2015 3:43:46 PM EDT
[#10]
Quote History
Quoted:

This is the standard method that everyone recommends. I've used it numerous times, however it doesn't always work.  
I just built a new upper this week, and I could not succeed.  30 lbs would leave 1/3 of a tooth in the way.  40/50/60/70/80 lbs was not enough to clear it.
I tried torquing and re-torquing at least a dozen times if not more.

I didn't want to lap the upper face because it's not clear that's a good thing to do in general.
So I ordered some 0.001"  barrel shims (3 for $10 shipped, from Bison Armory).  Popped one shim on and presto everything was good with just 40 libs.
IMHO this is the right solution if you don't succeed with 50-60 lbs.
View Quote View All Quotes
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Quote History
Quoted:
Quoted:
The technique that works best for me is to apply the grease to the upper's threads, insert the barrel and hand-tighten the barrel nut.  Starting with the nut hand tight, use an appropriate barrel nut wrench to torque the nut to 30 foot/lbs, then back it off.  Retorque to 30 ft/lb and back off.  Repeat once more.  Now torque to at least 30 ft/lb and line up the next notch on the barrel nut (without going above 80 ft/lb).

This is the standard method that everyone recommends. I've used it numerous times, however it doesn't always work.  
I just built a new upper this week, and I could not succeed.  30 lbs would leave 1/3 of a tooth in the way.  40/50/60/70/80 lbs was not enough to clear it.
I tried torquing and re-torquing at least a dozen times if not more.

I didn't want to lap the upper face because it's not clear that's a good thing to do in general.
So I ordered some 0.001"  barrel shims (3 for $10 shipped, from Bison Armory).  Popped one shim on and presto everything was good with just 40 libs.
IMHO this is the right solution if you don't succeed with 50-60 lbs.

It didn't work this time with those parts.  That's not the fault of the process; your barrel nut and upper just didn't get along.  I do not think there's any relationship between where the threads start and any notch on the barrel nut, nor any sort of standard for exactly where the upper's threads start, so you can basically wind up "throwing craps" and having the nut you're using just plain not work with the upper you're using.

I think using shims was a fine idea.  Another option is to use a different barrel nut.  This is why if you build more than a few uppers it's not a bad idea to have a few spare barrel nuts lying around.  It's a lot easier to just swap the nut and see if that fixes the alignment issue than to have to wait on shims, mess with the upper face, etc.



9/13/2015 4:00:35 PM EDT
[#11]
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Quoted:
Thanks for the tips guys , very good information. I'll get some Aeroshell 33MS
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Be sure to also apply a little grease to the shoulder inside the barrel nut that bears against the corresponding flange on the barrel extension.  Those two surfaces slide past each other while you are tightening and loosening the nut.

BTW, I also favor handguards with barrel nuts that don't require indexing for the gas tube.  My SLR Solo model tightens with a simple crescent wrench. - CW
9/15/2015 10:52:44 PM EDT
[#12]
Quote History
Quoted:
I think using shims was a fine idea.  Another option is to use a different barrel nut.  This is why if you build more than a few uppers it's not a bad idea to have a few spare barrel nuts lying around.  It's a lot easier to just swap the nut and see if that fixes the alignment issue than to have to wait on shims, mess with the upper face, etc.
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Agreed.  But in my case I was using a custom barrel nut (MI), I didn't have an extra one, and didn't feel like rolling the dice for $20 to see if another sample would work.  So many rails use custom nuts now, I still think shims are the best thing to keep on hand because they will ALWAYS work on any nut, any rail, and they're cheap.


9/16/2015 10:56:04 AM EDT
[#13]
Nothing wrong at all with using a shim.  They can be hard to find when you're in a pinch, though.
9/16/2015 11:21:14 AM EDT
[#14]
Quote History
Quoted:

Agreed.  But in my case I was using a custom barrel nut (MI), I didn't have an extra one, and didn't feel like rolling the dice for $20 to see if another sample would work.  So many rails use custom nuts now, I still think shims are the best thing to keep on hand because they will ALWAYS work on any nut, any rail, and they're cheap.


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Quoted:
Quoted:
I think using shims was a fine idea.  Another option is to use a different barrel nut.  This is why if you build more than a few uppers it's not a bad idea to have a few spare barrel nuts lying around.  It's a lot easier to just swap the nut and see if that fixes the alignment issue than to have to wait on shims, mess with the upper face, etc.

Agreed.  But in my case I was using a custom barrel nut (MI), I didn't have an extra one, and didn't feel like rolling the dice for $20 to see if another sample would work.  So many rails use custom nuts now, I still think shims are the best thing to keep on hand because they will ALWAYS work on any nut, any rail, and they're cheap.



That makes a big difference.  Custom parts often call for custom solutions.  Those steel MI nuts are really solid parts, but again, there's no guarantee that they will line up with any specific upper.  Good call on the shims - and on keeping them on hand.
9/16/2015 1:12:20 PM EDT
[#15]
I bought an Omega hand guard and it came with shims. I used one to clock the barrel nut to keep the torque below 50lbs even after lapping the receiver.

I've used a different torquing procedure and maybe I'm doing it wrong... I've been torquing to 30lbs, then increasing torque to where the barrel nut indexes with the receiver just allowing the gas tube to be inserted... then re-torque 2 more times. This is usually over 30lb, but not always.

One thing I've noticed when torquing a lapped receiver is less movement of the barrel nut as the torque goes up.... I believe the torque increases because of the larger surface area of the receiver in contact with the barrel extension so there is less compliance. Just an observation....
9/16/2015 1:32:19 PM EDT
[#16]
Nothing.
9/16/2015 5:25:15 PM EDT
[#17]
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Quoted:
Nothing wrong at all with using a shim.  They can be hard to find when you're in a pinch, though.
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That's why I always lap my upper receivers.  I can do a few thousandths extra if I need that extra 3 degrees to time the nut correctly, and ensure the barrel is truly alligned to the bore axis of the upper.
9/16/2015 6:02:12 PM EDT
[#18]
Here's why I didn't lap my upper...

http://www.ar15.com/forums/t_2_493/269790_Do_I_need_to_lap_a_Balios_Lite_upper_.html

From the 2A guy... he's saying using the BC bore as a reference is a bad idea, and that's what these lapping tools do:

"If the lapping tool can fit down the bore, it means that it's sitting inside that bore at an angle. even if it's a thousandth out on that bore, it will translate to a thousandth or more! out of square at the face of that receiver.

You could be doing damage by lapping that face.

EDIT:

After looking at these tools on line, I am going to go ahead and say that they are in fact TAKING THE FACE OUT OF SQUARE of the bore! The bore dimension for the extension is tighter than the dimension on the carrier bore. If you look at these tools, the pilot is inserted, and skips past the tightly held extension bore, and goes into the looser dimensioned carrier bore. So as this tool falls into the carrier bore, it is forcing the laping face out of square with the extension bore."


9/17/2015 1:44:44 AM EDT
[#19]
Just lap the receiver oriented vertical.
9/17/2015 4:21:39 PM EDT
[#20]
Motor oil will work great for upper receiver threads
9/17/2015 9:28:24 PM EDT
[#21]
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Quoted:
Motor oil will work great for upper receiver threads
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This, good old Mobil 1.

Vince
9/18/2015 12:53:51 AM EDT
[#22]
I just use a little gun grease.
Works fine.
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