AR15 ASSEMBLY TIME, almost.....

[x_wrench]

I have all the parts and tools (at least i "think" I do) and according to the tracking, it should be here Monday. I have been reading and watching videos on it, and I think I have a pretty good feel for the job at hand. yet, I still have a question or (?) about particular things, that only experienced persons will know. Larry Potterfield (whom I seriously respect) shows using anti seize on the barrel nut threads (instead of aero-shell 64 /33ms). I have not purchased this grease. I'm sure the "ms" is for molybdenum disulfide, which nowadays is quite common as opposed to 1960 anyway. i actually have 3 different containers of moly grease in my garage right now. anyway, back to Mr. Potterfields video, he only uses it (anti seize) in the barrel nut, and leaves the barrel/frame interface completely dry. is that a good idea? I'm a (disabled) mechanic by trade, and I have issues about mating aluminum to steel dry. in my field, that's a recipe for disaster (assuming you ever want to take it back apart some place down the road. //// I guess my next question is about lubricating the buffer/spring. Ive seen spray penatrating oil, spray grease (white lithium) and dry spray lube (probably graphite). what is the correct lube? FWIW, I am using a solid A2 stock, so I think that will keep the spring/buffer a little cleaner.
I look forward to reading your replies!!!

 

[Ethan Verity]

I coat the whole frame/barrel interface on my barrels with Aeroshell 33MS when installing. I figure it won't hurt anything, it may be helpful to prevent corrosion.. and it gives me peace of mind.

As for the buffer spring, I just wiped it down with some CLP every once in a great while. Same as you would with the other parts.

 

[mjsdwash]

Never heard of upper/barrel sticking, maybe left underwater. Aluminum and steel don't really mix corrosion all that much in practice, without some electrolyte involved.
Anything you put in there will melt out anyway with even 1 or 2 mag dumps worth of heat. I have heard of people filling the gap with locktite, but with no plan to ever separate them.
I would use the grease you have on hand. I used antiseize the last few times, but would have used grease if I remembered I had it at the time. The one place I would make damn sure to use antiseize is a flash hider. Thats to make the index work rather than preventing galling. I oil the buffer spring only when it gets water in it to prevent rust. I don't hear the noise people talk about.

 

[greyling22]

grease, anti seize (the best), nothing, they all work. it's not rocket science. I've seen nuts you can unscrew by hand, others I've had to freeze to take apart (I'm looking at you bear creek) Les Baer used about a half a bottle of loctite and I had to heat the nut to get it off.

I use some bearing grease on the buffer tube. not too much. about a jelly bean size amount.

 

[sarduy]

Just coat the threads and the barrel with anti-seize and be done with it. As for the rest of the rifle… well i use white lithium grease for the AK and synthetic Mobil One for the AR using my fingers, then just wipe everything down. If you need some more lube, drop two more drops in the bolt. As for the buffer/spring/tube just a light coat of oil or lithium grease.

 

[Skylerbone]

I’ve always used anti seize on the barrel extension and nut, Aeroshell on everything else. If you want to lubricate the receiver extension, try an old 12ga shotgun swab and a thin coating of Aero if anything. EDITED: clarifying, was thinking about internally on the receiver extension as someone had mentioned spring “twang”.

Building for accuracy sometimes involves Loctite or AcraGlass.

 

[MistWolf]

The manual calls for Aero Shell on the barrel nut. However, Never Seize works fine. Based on my experience in aviation, I recommend avoiding copper Never Seize when fitting aluminum to steel to avoid possible dissimilar metal corrosion.

There’s no reason to apply grease or anything else to the barrel extension where it fits in the upper. Some guys apply a coat of green Locktite to fill any possible gaps. When torquing the barrel nut, torque twice and back off. Final torque the third time. Barrel nut torque is 35 to 85 ft/lbs. Torque barrel nut to 35 and check alignment of gas tube notch. Tighten until you get good alignment but don’t exceed 85 ft/lbs. That said, don’t over think it. Basically you torque until the barrel nut is snug, check alignment, then tighten until it does line up.

Use of grease on receiver extension (RE) threads is not needed or recommended. Don’t go crazy when staking. It’s easy to drive the metal off the end plate into the threads of the RE and damage them. It also makes removing the end plate harder.

If you use a crush washer (not recommended) to install your muzzle device, be careful. It’s easy to over torque it and have it jam the threads making removal difficult. Shims are better than a crush washer.

Some people will suggest installing roll pins with a pair of Vise Grips. Don’t listen. I don’t have to tell you what kind of damage Vise Grip teeth can do.

Avoid future extraction issues by installing a Colt extractor spring now.

Using a slave pin to hold the trigger and semi auto sear during installation will save you aggravation. Clean and grease the trigger & hammer before installation.

Take care not to cross thread the pistol grip screw.

The detent pin for the forward take down pin is easy to launch into orbit. There’s a specialty tool that makes installation easier and working inside a large plastic bag makes finding the pin easier after launch.

Take your time and pay attention to every step of the assembly and it will go together easy.

 

[bfoosh006]

You might enjoy these videos as well... I don't use all the "tricks" but I do lap the upper receiver, and certainly Loctite the barrel in.
Part 3 around the 50 second point.

FYI... the Brownells Lapping tool has been a better fit in Thermal fit uppers ( BCM ), and the PTG lapping tool has been a better fit in Non-Thermal Fit uppers.
DO NOT buy the Wheeler lapping tool... a VERY poor fit in every upper I tried.

https://criterionbarrels.com/media/accurizing-the-ar-15-video-series/?v=7516fd43adaa

 

[Skylerbone]

You might enjoy these videos as well... I don't use all the "tricks" but I do lap the upper receiver, and certainly Loctite the barrel in.
Part 3 around the 50 second point.

FYI... the Brownells Lapping tool has been a better fit in Thermal fit uppers ( BCM ), and the PTG lapping tool has been a better fit in Non-Thermal Fit uppers.
DO NOT buy the Wheeler lapping tool... a VERY poor fit in every upper I tried.

https://criterionbarrels.com/media/accurizing-the-ar-15-video-series/?v=7516fd43adaa

I’ve never had an issue with the Wheeler but I would emphasize that lapping is not to be overdone. Even contact at multiple points around the circumference, don’t grind it down.

 

[Chuck R.]

I’ve never had an issue with the Wheeler but I would emphasize that lapping is not to be overdone. Even contact at multiple points around the circumference, don’t grind it down.

Agreed!

I now lap all of my uppers as I get them.

Just found an added benefit this morning. I have almost finished another AR built to be my "calling" coyote carbine. I was just using my 3Gun rig, but last year I went to a brake that justifies doubling up on the ear pro, never mind using it for hunting. Unfortunately the scope I really want; Leupold MK3 3-9 HD, illuminated TMR is on serious backorder, so I decided to take the scope off my 3Gun rig since the match season is over.

The Leupold 1-6X 6HD resides in an ADM recon mount. Went to zero it at 25 & 200 yds today with a 55 Nolser BT load and it was just 4 clicks left and 2 high from my 3Gun zero with 55 FMJ. About the same delta I normally see when changing loads.

Might just be dumb luck, or maybe there's something to squaring chit up.

 

[bassjam]

The funny thing about firearms, and AR15's in particular, is even the manufacturers don't necessarily agree on what should be done. Which tells me there's not a single "right" answer but there's plenty of good options that work as well as another option (unless maybe you're in extreme sub-zero conditions). I've used Valvoline wheel bearing grease on the barrel extension and barrel nut. I've used blue threadlocker on another barrel extension and wheel bearing grease on the barrel nut. It came loose fine a couple years later with a few light taps with a large wooden dowel through the upper. Lately I've been using Lucas extreme duty gun grease on the barrel extension and nut.

As to the buffer spring, I dropped a dollop of wheel bearing grease in my palm and spun the spring through it on my M&P Sport to get rid of the "sproing" sound, and it's did the job. Really buffer springs don't need lubed other than maybe wipe it down with an oily rag every now and then to keep it clean but I only did it to cut down on the noise. All my other AR's I've switched to silicone coated springs which I like quite a bit, they're quiet without needing any lube.

 

[Lo-Profile]

I coat the threads on the barrel nut with automotive style anti-seize .... Have on all my builds over the past 20+ years, never a problem