Ready to start build, couple of questions

[Creeky73]

ok guys, I think I am finally ready to start putting together my build. One question I have is about whether or not it is necessary or recommended to lube the gun as you are building it. Most of the assembly vids I have seen just pretty much show guys taking parts right off the table and putting the gun together, with little to no lubes or chemicals involved. So am I to assume that all of the lubing can be done after the build is complete?

my other question is about the proper torque for the barrel. I have seen a few common answers, some saying just over 30lbs, some say 50lbs, and a lot don't even use a torque wrench. I intend to use a torque wrench and would like to know what the proper torque would be on say a 20" barrel on a standard forged M4 upper?

Any help is appreciated [:D]

[Eric]

I always use a bit of CLP during assembly, especially when driving in roll pins. The FCG is another area that gets CLP during the build. Prior to use the entire weapon gets a proper application of CLP, a bit on the heavy side, which is helpful during the initial break-in.

The TM procedure is to apply moly grease to the threads, torque the barrel nut assembly three times to seat the threads. On the last one, torque a min of 30 ft-lbs and a max of 80 ft-lbs. This is a fairly wide range and you just want to ensure that your gas tube hole is properly lined up to avoid throwing the gas tube off to the side.

M16 Technical Manual - TM9-1005-319-23&P (http://www.weaponevolution.com/forum/downloads.php?do=file&id=7) On the far right, click the download button.

[Quib]

Detents And Springs

I like to lube springs and detents as I progress through the build. My theory behind this is, do it now while you have complete access to the parts. Once installed, it might be harder for the lube applied to migrate to these hard to reach areas.

It might be years until some of these detents and springs see the light of day. You want to assure you get complete lubrication coverage to prevent the possibility of corrosion forming.

Follow up after assembly, during your routine maintenance, with lube applied externally. Allow this lube to work its way in, resting assured that you have the full protection and lubrication required from the lube applied during assembly.



Fire Control Group (FCG)

Here I personally like to lightly apply Tetra Grease to the Hammer and Trigger Pins. Again, lube now, while you have complete access to the parts. Follow up during your routine maintenance, with lube applied externally.

ETA: Parts such as the FCG, usually come from the dealer or distributor covered in Corrosion Prevention Compound or CPC for short. This CPC is most often thick and tacky, naturally to help promote adhesion to the parts while in storage. Before assembling the FCG, or parts covered in CPC, I like to thoroughly wash all CPC from the surfaces with Odorless Mineral Spirits. Now that the parts are clean and free of CPC, they can be wiped down with a damp CLP rag and are ready for assembly/installation.



Grease

The only sections in the -23&P that call for grease lubrication, are the assembly sections pertaining to the Barrel Nut, Upper Receiver threads and the Lower Receiver Extension.

The grease called out by the TM is:

GREASE, MOLYBDENUM DISULFIDE
9150-00-754-2595
MIL-G-21164

Any good quality grease should suffice. I personally use Lubriplate. One caution to keep in mind with off the shelf commercial automotive grease, is the content of graphite in the grease, which is said to cause corrosion in aluminum.

If one wishes to use this exact Mil-Spec grease as called for by the TM, Aeroshell 33MS meets this spec, and can be easily obtained at:

http://www.skygeek.com/5067068.html


AeroShell Grease 33MS is an extreme pressure (EP) grease based on the proven lithium complex technology of AeroShell Grease 33, and is fortified with 5% Molybdenum Disulphide. The benefits of Grease 33MS include: Improved anti-wear and corrosion resistance over AeroShell Grease 17; It is fully compatible with AeroShell Grease 33, so reduces the risks and problems associated with misapplication; Load carrying and EP properties equal to that of the well established AeroShell Grease 17; Fully approved to MIL-G-21164D. It possesses enhanced anti-wear and anti-corrosion properties and is particularly suitable for lubricating heavily loaded sliding steel surfaces, such as, for example, bogie pivot pins on aircraft landing gear-assemblies. AeroShell Grease 33MS is a direct alternative to AeroShell Grease 17, but when changing from (clay-based) ASG 17 to (Li-complex based) ASG 33MS, the normal rules on grease changing should be applied.



Barrel Nut Torque

The Barrel Nut Torque specs and the sequence for torquing, can be found in the link above provided by Eric. One thing to keep in mind, is the torquing of the barrel nut is a “wet torque”. The grease applied during assembly, plays a very important roll in obtaining a tight barrel nut.

The dry threads of a steel Barrel Nut, tightening against the dry threads of an anodized Upper Receiver, can very quickly lead to “galling” of the threads. This will result in a barrel nut frozen to the Upper Receiver.

Applying grease to these threads, in combination with the “tighten-loosen sequence” called for by the TM, will ensure that the threads of the Barrel Nut and Upper Receiver have a chance to “run-in” and mate with each other. Following these procedures will ensure you are reaching the correct torque, that the Barrel Nut and Upper Receiver are properly tightened, and a loose Barrel will not cause problems later down the road.