Anti-seize grease on PCC barrel?

[Cy Soto]

I understand the need of using anti-seize grease when installing a new barrel on an AR-15 or AR-10 platform but, is grease necessary (or even recommended) for a 9mm PCC? I ask because I don't believe that a 9mm PCC can generate enough heat at the barrel to fuse it to the upper receiver.  Is this true?

[Chip3]

What is the disadvantage of using an anti-seize or grease? I think it is the dissimilar metals not heat that you are using the coating for. The anodize of the aluminum and something like a melonite barrel may help keep them from bonding on a 9mm.

[Marshal82]

It's not the heat. The grease serves a couple purposes, first to keep from galling the threads when you tighten the nut. Second is it serves as an anti seize to keep corrosion from happening. The grease just needs to withstand the temps of firing so it doesn't run out and stays effective. 

Use grease, it helps. 

[Dannybot]

Do you have anti-rotation tabs on your handguard?  If not, you might rethink the antisieze, there is no gas tube to keep the barrel nut from backing off.  I noticed my handguard backed off a couple degree after a few hundred rounds.

[Cy Soto]

Yes I do have anti rotation tabs on the hand guard. It's an MI Gen3 so that won't be much of an issue.

My reason for the anti seize grease question is because (at some point) I may want to SBR this system and I would like to be able to salvage the upper if I need to.

Sent from my Nexus 6P using Tapatalk

[MikeRush]

Grease the receiver/barrel nut threads to prevent galling and corrosion.

Typically you don't need to do anything to the interface between the barrel itself and the upper. On PCCs I am now using red loctite between barrel and upper, then grease on handguard/barrel nut threads. It takes a propane torch and dowel to get barrel out of the receiver, but it prevents the blowback bolt from hammering the barrel enough to cause the barrel nut to back off. 

[Flatland Shooter]

2 hours ago, MikeRush said:

On PCCs I am now using red loctite between barrel and upper, then grease on handguard/barrel nut threads. It takes a propane torch and dowel to get barrel out of the receiver, but it prevents the blowback bolt from hammering the barrel enough to cause the barrel nut to back off. 

Do you torque the barrel nut to the same specs as 5.56 or less?

Thanks.

[Cy Soto]

Do you torque the barrel nut to the same specs as 5.56 or less?

Thanks.

I went by the recommendation of the manufacturer and torqued to 40ft/lb.

I typically torque 5.56mm barrels to 35ft/lb but this may also be affected by having to line up the gas tube. No gas tube to worry about on a 9mm blowback system.

[MikeRush]

1 hour ago, Flatland Shooter said:

Do you torque the barrel nut to the same specs as 5.56 or less?

Thanks.

I torque them to same as 5.56. I figure by using the loctite to bond the barrel to the upper I am taking away from the extra impact imparted to the nut by the blowback system. I believe JP uses the red on factory builds, and that Alexander Arms uses thread locker on their exotic uppers.

I have heard green is better for this purpose but I have found red to be adequate. I have bedded .223s this way as well when I know I am happy with the barrel/upper combo.