WHAT ANTI-SEIZE COMPOUND ON AR BARREL NUT?

[StanCT]

Greetings, gents -

BCM instructions call for moly paste to lube barrel nut threads during handguard installation.

Question to those that have done this before:

Can I make equal use of a Copaslip-type compound without adverse effect?

Could / should I also use the stuff (sparingly) on the mating surfaces of LP gasblock during installation?

[Stevin]

Of all the AR's i've assembled i've used a small amount of copper slip, however any sort of moly grease should work as well.

I would not use any lube on a gas block, the fit should be a fairly tight slip fit, some barrels / blocks even require a thermal fit.

[oafpatroll]

I've used coppaslip on stuff that gets an awful lot hotter than rifle barrels and always had great results. Can't think of why it wouldn't work well.

[StanCT]

Thank you, Gents.

[A-R]

Keep in mind that Copper Compound (Coppa Slip etc.) is basically grease with some powdered copper particles mixed in. The purpose of this copper powder is to remain in there when the grease has long been burnt away by high heat. The particles form a thin barrier between the 2 steel or other material parts, preventing them from seizing together.

On a barrel nut I would not mind using copper compound, as it will not likely help the nut to loosen during use, but help when you want to remove it again for whatever reason.

On a gas block, the tight fit will likely push the copper particles out when forcing it over the barrel. Moly grease would be the better option i.m.h.o.

[Stevin]

Keep in mind that Copper Compound (Coppa Slip etc.) is basically grease with some powdered copper particles mixed in. The purpose of this copper powder is to remain in there when the grease has long been burnt away by high heat. The particles form a thin barrier between the 2 steel or other material parts, preventing them from seizing together.

On a barrel nut I would not mind using copper compound, as it will not likely help the nut to loosen during use, but help when you want to remove it again for whatever reason.

On a gas block, the tight fit will likely push the copper particles out when forcing it over the barrel. Moly grease would be the better option i.m.h.o.

The US Army M4 manual call out for no grease on the gas block. Although the manual I have is from the A-Post Era. I can't see it being any different for a low profile block. If anything my mind says no lube, as they typically have a weaker fixture system, and could possible shift under recoil with added lubrication if the fit is sloppy.

[oafpatroll]

It makes sense to me that a gas tight joint wouldn't want grease.