Grease on barrel shoulders

[Alex Wheeler]

I saw a video by a gunsmith recommending to not put any grease on the barrel shoulder when torqueing a barrel. I am sure this probably originated from some of the testing done in "rifle accuracy facts". I think its a great book and a lot of effort went into it, but keep in mind the instrument used to detect barrel movement had an error of about 3 times the size of the groups a modern bench rifle is capable of and the barreled action use was a relatively inaccurate .270 win. In no way am I trying to knock what was done with the equipment used, but I have pulled barrels off with nasty galling on the barrel shoulder. Grease on a shoulder is not going to hurt accuracy but a big raised gall will.

 

[Fuj]

Nutted or shouldered,, I've always used Lubri-Plate
lightly with a Q-Tip.

 

[AlNyhus]

Alex, I've always lubed them and have tried a variety of shoulder lubes...EP stuff, synthetics, Imperial sizing die lube, various anti-seizes, etc. and have come to my own conclusions.

Do you have a favorite?

Good shootin' -Al

 

[NorCalMikie]

The SQUEAKY barrel gets the grease.

 

[Mulligan]

Alex, I've always lubed them and have tried a variety of shoulder lubes...EP stuff, synthetics, Imperial sizing die lube, various anti-seizes, etc. and have come to my own conclusions.

Do you have a favorite?

Good shootin' -Al

What are those conclusions? What have you found that works best?
CW

 

[akajun]

Im an anti seize guy, only because Ive fought with stuff assembled with grease over the years that has dried and cemented itself almost as bad as rust.

 

[jackieschmidt]

If you are going to use a lubricant on a mating surface or threads, it’s a pretty good policy to use something that is actually designed for that purpose.

I use gray anti-seize. This in particular because we buy a lot of it for use in our Shop.

15502 - Jet-Lube 550 1/2 lb Brushtop Can

Nonmetallic Anti-Seize & Thread Lubricant A premium formulation for a wide variety of applications over a wide temperature range. 550 is well-suited for most maintenance needs. Its composition offers reliable protection against seizure and heat-freeze, eases assembling and dismantling and...

www.industrialstop.com

AS for it being on the action face, yes. Most of our shooting applications are stainless on stainless. A very thin film is all you need.

Not only does it avoid the two faces galling, it also cuts the friction so the barrel shoulder will actually advance so as to impart the proper tension on the treaded joint.

 

[X Ring Accuracy]

If you are going to use a lubricant on a mating surface or threads, it’s a pretty good policy to use something that is actually designed for that purpose.

I use gray anti-seize. This in particular because we buy a lot of it for use in our Shop.

15502 - Jet-Lube 550 1/2 lb Brushtop Can

Nonmetallic Anti-Seize & Thread Lubricant A premium formulation for a wide variety of applications over a wide temperature range. 550 is well-suited for most maintenance needs. Its composition offers reliable protection against seizure and heat-freeze, eases assembling and dismantling and...

www.industrialstop.com

AS for it being on the action face, yes. Most of our shooting applications are stainless on stainless. A very thin film is all you need.

Not only does it avoid the two faces galling, it also cuts the friction so the barrel shoulder will actually advance so as to impart the proper tension on the treaded joint.

BINGO!

 

[BoydAllen]

After seeing the grey anti-seize pile up to some thickness in the shoulder interface, I started wiping it off and applying a thin film of Pro Shot Gold. I never had any functional problems either way, but I did not like the idea of the little bit of added thickness. the main thing that I got from Vaugn's book was that one should avoid teflon products in the barrel to action joint.

 

[Alex Wheeler]

Alex, I've always lubed them and have tried a variety of shoulder lubes...EP stuff, synthetics, Imperial sizing die lube, various anti-seizes, etc. and have come to my own conclusions.

Do you have a favorite?

Good shootin' -Al

Al,
I would not say I have a favorite for accuracy but I do have favorites that achieve what I want. Most of my limited knowledge of fasteners comes from the studying I did on the subject when I was still into drag racing. Knowing that the clamping force of a joint comes from stretching the fastener and we are working with pretty low torque values for the size "bolt" we are dealing with I want a high quality lube that reduces friction in the joint so the torque can actually be applied to stretch the fastener as much as possible. Poor quality lubes or a dry joint is going to limit that. I have never seen anything to make me think the barrel joint was moving. It cant move axially thanks to the shoulder (why I dont like nuts) and it would have to fight the centering force of the 60 degree thread to move radially. So I prefer high quality moly based grease or teflon based grease. However thats more of personal thing I think any decent grease if fine. I do try to keep track of as many things as possible about any rifles that have set records or been exceptional in any ways to try to see if any trends rise up. I can say moly, teflon, and anti seize have all found their way into the record books, most of them teflon based though.

 

[Edd]

After seeing the grey anti-seize pile up to some thickness in the shoulder interface, I started wiping it off and applying a thin film of Pro Shot Gold. I never had any functional problems either way, but I did not like the idea of the little bit of added thickness. the main thing that I got from Vaugn's book was that one should avoid teflon products in the barrel to action joint.

What is the issue with using teflon products?

 

[BoydAllen]

What is the issue with using teflon products?

He looked at movement in the joint with a variety of materials and one of them was teflon tape (if memory serves). My early Stiller Viper's thread/lug insert was thread milled, and has a distinctive uniform texture that I think is a good thing. I want all the friction in the joint that I can get, without galling. Every so many barrel changes I clean out the action threads with an old tooth brush and solvent, so that they do not accumulate anti-seize. When I apply anti-seize I use an acid flux brush and put on just enough to color the metal uniformly....as thin as I can get it. Never had a problem. I tighten them pretty tight. I should say that I have several barrels for this rifle, and switch them more often than I would be if I only change when worn out.

 

[vonb]

I was told by Zermatt upon purchasing to make sure I used anti-seize on threads, shoulder/receiver face. They mentioned they had seen issues where not using it on face/shoulders would cause the pins to snap for the recoil lug upon torquing of barrel.

 

[Alex Wheeler]

He looked at movement in the joint with a variety of materials and one of them was teflon tape (if memory serves). My early Stiller Viper's thread/lug insert was thread milled, and has a distinctive uniform texture that I think is a good thing. I want all the friction in the joint that I can get, without galling. Every so many barrel changes I clean out the action threads with an old tooth brush and solvent, so that they do not accumulate anti-seize. When I apply anti-seize I use an acid flux brush and put on just enough to color the metal uniformly....as thin as I can get it. Never had a problem. I tighten them pretty tight. I should say that I have several barrels for this rifle, and switch them more often than I would be if I only change when worn out.

I do agree with your statement about the anti seize. You can see the metallic build up on a shoulder thats been torqued. Sometimes its difficult to clean off. While I have never traced it to any issues, I dont like it. I totally disagree with what was found with teflon. Just this year, a couple of my customers will be submitting for 9 new IBS records, they used teflon based grease on the tenons. As well as many others. I can tell you if the machine work is good, you about give your self a hernia getting a barrel off with that grease even if you torque it mildly. I will pull out my big torque wrench next time I pull one to see what it takes, but I was was a mechanic for about 15 years and I would say if you put them on a 75lb it takes at least double to break them loose. If they are just unscrewing "softly" without a big "pop" with they break loose the fit of the barrel to the action is at fault, most of the time threads that are too tight. Any more friction in that joint and I would not be able to get them off.

 

[AlNyhus]

Super Lube #21030 with PTFE is what I use on tenons and the barrel shoulder/action face. There's lots of stuff out there that works well...most any quality EP lube will do the trick.

For an anti seize, a non-metallic like the Jet Lube Jackie referenced would be my preference. -Al

 

[Dusty Stevens]

I do agree with your statement about the anti seize. You can see the metallic build up on a shoulder thats been torqued. Sometimes its difficult to clean off. While I have never traced it to any issues, I dont like it. I totally disagree with what was found with teflon. Just this year, a couple of my customers will be submitting for 9 new IBS records, they used teflon based grease on the tenons. As well as many others. I can tell you if the machine work is good, you about give your self a hernia getting a barrel off with that grease even if you torque it mildly. I will pull out my big torque wrench next time I pull one to see what it takes, but I was was a mechanic for about 15 years and I would say if you put them on a 75lb it takes at least double to break them loose. If they are just unscrewing "softly" without a big "pop" with they break loose the fit of the barrel to the action is at fault, most of the time threads that are too tight. Any more friction in that joint and I would not be able to get them off.

They are actually talking about teflon tape, like a plumber would use, not the teflon grease which is very good. As long as it doesnt have metal in it and is a good high pressure grease i like it. These barrel joints do not get hot enough to boil the grease out (which is the purpose in the metal in the anti seize).

 

[jelenko]

A tangent.
What antiseize should be used on the barrel nut for an AR 15? I'm using one with copper in it. I'm applying ~ 75-80 ft-lbs. I don't think it matters, but this is a barrel nut on a 'match' rifle - the nut is just a long cylinder with threads inside for part of the length. The nut does not snug up against the upper receiver; it snugs up to the stainless barrel extension.

 

[rijndael]

A tangent.
What antiseize should be used on the barrel nut for an AR 15?

Aeroshell 33MS is quite popular with AR guys. It has moly in it.

 

[jelenko]

Wow. It's even mil spec for ar barrel nut threads!

ETA: Turns out I have some aeroshell 7 and a bunch of Molybdenum Disulphide! In fact, I've been using a mixture of it for lubing my Geissele triggers.

 

[rijndael]

FWIW: In ARs, folks are concerned with galvanic corrosion (steel nut and aluminum upper), so they want to avoid greases with graphite.