Barrel and Upper Prep

[aatactical]

Before you put the barrel nut on your upper I was told to get a Q tip and put a small amount of high temp non graphite Disc Brake grease on the Upper Threads so as to keep the barrel from I guess seizing together making it possible to loosen without a problem. Anyone hear of this or have any other ideas thanks

[Dave L.]

I put this (http://www.brownells.com/aspx/ns/store/ProductDetail.aspx?p=20900&title=C5-A%20ANTI-SEIZE%20LUBRICANT)on the upper receiver threads. I believe it's the recommended product.

[sinister]

Correct, or Moly-Slide moly paste lubricant. In a pinch you can also use military GAA (Grease, Automotive), Lubriplate, or plain light, white grease.

What you don't want (if you can avoid it) is galling your threads (especially if you use retard strength and a cheater bar to exceed the -24 specified value to tighten down your barrel locking nut).

[aatactical]

That sounds good now about putting on the barrel what is the correct torque for the barrel. I ordered a dpms claw but havent gotten it yet any other ways to install barrel without it thanks

[warpigM-4]

That sounds good now about putting on the barrel what is the correct torque for the barrel. I ordered a dpms claw but havent gotten it yet any other ways to install barrel without it thanks

30ft/lbs wait for your claw.I had a buddy's cousin crush a upper with a home made upper clamp he designed

[aatactical]

Sounds good thanks for that info

[Iraqgunz]

Your torque specifications will fall between 30-80ft-lbs. You shouldn't exceed 80 ft.-lbs. Since this is potentially your first time doing it I highly recommend using a torque wrench. The best way is to tighten 3 times with the 3rd time being the final time when you tighten it. This along with the anti seize should help you.


Sounds good thanks for that info

[aatactical]

thanks for the info

[An Undocumented Worker]

Do you set the torque wrench to 30 ft lbs or do you have to calculate and compensate for the additional length added to the torque head by the barrel nut wrench?

I ask this, because when you using crows feet extension on torque wrenches you have to compensate for the additional lenght so as not to overdue the torque.

[Iraqgunz]

AUW,

Couldn't tell yo uas I do not use a torque wrench when I do barrel installs. As far as I know you simply set the wrench, put into the barrel wrench and the tighten. 30 would be the minimum needed to achieve proper alignment and 80 the max. Wish I had a better answer.


Do you set the torque wrench to 30 ft lbs or do you have to calculate and compensate for the additional length added to the torque head by the barrel nut wrench?

I ask this, because when you using crows feet extension on torque wrenches you have to compensate for the additional lenght so as not to overdue the torque.

[bkb0000]

Do you set the torque wrench to 30 ft lbs or do you have to calculate and compensate for the additional length added to the torque head by the barrel nut wrench?

I ask this, because when you using crows feet extension on torque wrenches you have to compensate for the additional lenght so as not to overdue the torque.

so long as your torquer is within a few inches i would imagine you're fine. 30-80fpi is a LOT of cushion. i've actually stopped torque-wrenching my barrels, as it doesn't seem to offer any benefit. snug it up three times, line it up, put your guard on.

and as far as anti-seize goes- i just use moly-lithium grease from walmart. $1. any grease works.

[aatactical]

I heard also that you really cant tighten but so far in order for the gas tube hole to line up with one of the holes in the barrel nut and I also heard the three time deal also. This grease is it high temp and is it the same grease you use to pack wheel bearings on a car.

[nicholst55]

Especially using the tools that are available to the military, it's very difficult to torque much over 30 ft-lbs. The wrench usually slips and strips teeth on the barrel nut if you try to go much beyond 30 ft-lbs - at least that's been my experience over the last 30 years or so. Normally the barrel nut lines up pretty close at that point anyway.

The -23&P TM specifies both the moly grease and the 'tighten 3 times' routine. FWIW, Colt doesn't apply moly grease on M4s at the factory - at least none of the ones that I've seen.

As far as what grease to use, I bought a pound of wheel bearing grease at Wal-Mart for right around $2, and that's what I've been using for several years.

[aatactical]

You know I am lost on the three time thing do you hand tighted the barrel nut with barrel installed then loosen it and repeat this again and again for the third time and when your doing it the third time thats when you lets say torque it down till one on the gas tube holes line up. By no means am I an idiot just dont want to screw up.

[bkb0000]

You know I am lost on the three time thing do you hand tighted the barrel nut with barrel installed then loosen it and repeat this again and again for the third time and when your doing it the third time thats when you lets say torque it down till one on the gas tube holes line up. By no means am I an idiot just dont want to screw up.

you'll have to give it something more than 80fp to thread it, and that's pretty much the only way you can **** it up. i've had barrel nuts that simply would NOT torque up to a hole- and ended up, in my opinion at the time, having to over-tighten to get a hole and not have it be loose. i haven't ****ed one up yet.