Hey, guys, I've got a pretty unique build going on but have hit a bit of a roadblock. From what I understand in regards to barreling an upper receiver, you are supposed to grease the barrel and upper threads, insert the barrel into the receiver, put together the delta ring assembly then... you gotta align the delta ring assembly hole with the barrel nut hole for the gas tube between 30 and 80 foot pounds of pressure.

So, to do this last step, you would normally get an armorer's wrench hit it as far as it'll go, back it off, hit, back off, etc. until it is aligned and in spec between 30 and 80 foot pounds. My problem is I have ask for help from someone who is insisting on doing this somewhat differently. He wants to just hit the barrel nut without backing it off until it lines up and doesn't want to bother with the torque wrench at all. What kind of problems can this cause, and am I better off waiting 6 months until I can do this myself properly? Basically, how badly will not checking the torque and not backing off the barrel nut screw me? Build is a C7 upper with a 20in A2 barrel.

Honestly, it’ll probably be just fine. Doing that whole process has for me seemed to stretch the threads to the point where I’m needing to go to the higher range in torque to get it to line up where it would have around 30 if I’d just stopped there...

Would like to hear more informed opinion though

He's stuck in his old ways. It's good to hear though that it will at least work the way he wants it done. It's a brand new upper. It just looks that way because of the lighting and the grease residue. By the way, does anyone know if lithium grease will harm a finish? Do I need to immediately take it off, or will it be fine to sit for a while?

Agree.
I torque mine because I have a garage full of tools so I make excuses to use them.
But it stands that, the gas tube hole, in my experience, usually only lines up in one spot and going past it always ends up in over-torque, and using the hole before it usually ends up in under-torque.
I do however, tighten to the correct position, loosen, and re-tighten. I do it 3 times then do a final tightening. I dont think a torque wrench is necessary to properly install a mil spec barrel nut/delta ring setup. For other barrel nuts that dont require any type of alignment (geissele), I prefer it.

Also, I recommend some aeroshell 33 on the threads, and no, lithium wont hurt the receiver, but no reason to have it on there.

I also dont think there is going to be any issue by not doing the re-tighten method. Where you just go to the final torque off the bat. I only do it because it was what I was taught and I have nothing better to do usually so it makes me waste more time.

I go to the first Notch after 30 foot pounds and stop. I have been doing this for years and I've never had anything come loose.

I've actually torqued one barrel nut with a torque wrench in all my builds.
Since then I use German torque, "goodntite" . I lube the barrel and extension with any good waterproof chassis lube if Aeroshell 33MS/Aeroshell 64 is not on hand.
I do an initial tighten to snug then back it off, then again once more and then a final tighten to get gas tube alignment.

I've never had an issue in 20 years.

Sometimes the wrong tool for a job can have a pulse and social security number.

It'll be "okay" but it's not the proper method. Those who reject proper procedure out of irrationality don't deserve any help. Leave them to figure their own stuff out.

Why would one not use a torque wrench?  They're $40 on Amazon.

I have not used a torque wrench for a quite a while now, you get a feel for it and there is a large range on these guns for what is the proper torque.

He even owns a torque wrench. I have no idea why he won't use it.

He refuses to use the torque wrench?
Is he one of those old crusty goofs that wont use tools made after 1918?

I would have zero problem with his method. It's really not that complicated and will pose zero issues.

It is an easy thing to do it by the TM method. If you think you have the feel for 30 ft pounds using a straight 1/2" bar on the barrel wrench you don't even have to take the wrench off to do it three times and it takes no time to do. Then just put the torque wrench on it and finish up the install.
No way I would install a barrel with one of those cheap plastic blocks that slide in the upper from the bottom and has a pin for the front lug if that is what was being used.

This is it exactly,

I use plenty of mil-spec grease and follow the tightening procedure in the TM.

There is a reason for torquing 3 times.

Setting the threads became a thing relitively early in the M16's life after armorers for basic training units were having a lot of wandering zero issues caused by loose barrel nuts. Or so the oral history goes.

Granted, these are guns that get a fair amount of abuse.

Point being, "good enough" simply isn't unless you really don't give a shit about a stupid range toy.

OP, your buddy is a moron.

Torque your barrel the right way and don't let some mental midget dictate how you build your guns.

Real world use has proven the three torque to between 30 and 80 ft lbs works and works well. Stick with it and you'll never regret it or find yourself wondering why, or "what if?".

Me too. I’ve never “seasoned” the threads by doing it three times either. Aeroshell on the threads, hand tighten, and then torque it to spec. Never had an issue and I have quite a few hard use rifles.

I doubt the OP came to the tech forums to learn how to do things wrong....

Maybe it's just a wild fantasy that "tech forums" would be used to disseminate actual technical information.

But i've been know to be wrong about things before.

The tight&loose process is needed in case the barrel nut is difficult to align with the gas tube hole without  exceeding the torque spec by doing it in one single step..

If the barrel nut align perfectly the first time within torque spec   I don’t see any issue.

As for the torque wrench use.. it all depends on the experience of the armorer... I’ve never used one in 20yrs of assembling uppers... but I know by feeling when too much force is too much..

Seasoning the threads is a important step in building an AR.  No two threads are identical, there will always be a minuet difference. Seasoning the threads mates the nut with the receiver by forming the softer material to fit the nut. You may never know the difference but why not do it right.

@coldblue

So even you don't do the torque three times to 30 foot pounds routine as long as it lines up on the first go? When you say "if enough torque is applied" do you mean more than the 30 foot pound minimum?

I admit that I've always stuck to the manual and did the torque three times to 30 foot pounds routine.

I agree that the setup being used in the OPs picture is all kinds of not adequate enough for the job.

You sometimes have to pull a lot of weeds to find the people that know what they are talking about here, and actually the same applies to most internet forums.

For those not aware @coldblue is personally responsible for the A2 or M4 (help me out @coldblue) development program and not just the guy at the desk, but also the guy in the machine shop and the guy conducting the tests. (Note his industry partner logo and you can read some real interesting development tech in the retro forum and other tech forums he posts in)

I'm well aware, his advice to me is highly respected.

Topic Moved

Been doing it this way as well.

$9 at Harbor Freight.

Because it's basically pointless?

You have to hit the notch for the gas tube either way. So setting to a specific torque is kind of pointless

I agree, your advice here is also highly respected by me, it's never found in any of the weeds that I have to pull that I mentioned.

Same.

What kind of receiver block are you using? Looks like it was cut in half and has no rear pin attachment. It along with the workmate bench looks inadequate. Does not look like enough support for the receiver or the weird looking receiver block. The upper and delta ring  looks really beat up.  Did someone try to clamp the receiver under the carry handle? Any internal damage in the C7 upper? Also looks like you need triangular hand guards. Is this a hybrid retro build?

Before you do more damage you need better tools.

1. Aeroshell 64
2. Season the threads
3. Use a torque wrench

Gootntite is inconsistent and I’m not poor, so I use the proper tools.

It's from the Crosstac receiver block set. > https://www.crosstac.com/shop-all-products/ar-15-maintenance-block-full-kit-with-hammer-block-and-roll-pin-punch/

It's not made for barrel installation at all, but it's great for the bolt catch roll pin.

Coldblue is the most qualified poster commenting in this thread by far. This should answer any debate about Torquing the barrel nut,OP. Notice he doesn’t say anything about “seasoning” the threads. It’s not needed.

It really depends on whether you trust him or not. Barrel nuts that have to be indexed are easy to get right if you have a feel for it. If you've done it enough times, you'll know if it feels like it's not aligning at the correct torque.

What bothers me is why he would refuse to season the threads. That makes no sense whatsoever. Because of that, I don't think I would let him touch my guns.

There is no "final" torque, which is where the AR community gets it all wrong. It's not a "torque TO" figure, it's a "Do not EXCEED" figure to keep from stripping the threads.

If the nut won't line up under 80 pounds, the factories pick a different one or lap it. When you have a parts bin with dozens - and they are not indexed to any particular start point - then the gas slots and threads aren't indexed. They are random. Next random combination might work well, minor chance of being worse.

We don't have a bin of nuts, we just have the one (if the wife let you even keep it) so we shim or lap, and that's only when it's needed. Some lap every upper, it's usually enough to get almost all the anodizing to the same squareness but it's not guaranteed to leave it alignable.

We just take our chances on that. Since it's a matter of turning the nut just to get it to align, experienced mechanics who have torqued a lot of stuff don't need a torque wrench. Goes to installing a water pump vs head gasket - I've never heard or seen anyone torque water pump bolts, they hand tighten and move one. A head gasket needs the correct rotation and torque buildup to prevent breaching the seal when running.

This is water pump level tightening. The lug nuts on your car are more important to get "right." And for all that, how many put Aeroshell on them? They suffer years of use in a corrosive environment and we don't do squat for them, yet OMG you better put special grease on your AR15 or - what? Nobody has ever shown pics of a rusted off upper. They might corrode slightly but we are talking salt water immersion. Not to many of us do that.

If you have the feel to torque lug nuts to 80 foot pounds then the rule for the AR is - don't. The 80 is a do not exceed. The spec is a 50 foot pound wide range, which is hardly a precision setting.

I did my first two with a set of 18" channel lock pliers. Later I got the wrench and it's really no easier. What really helped was a set of vice blocks. Don't strip the threads, is all. And remember, if you are working on the muzzle device, clamp the barrel. The only thing holding the barrel extension on is that pin jammed into the threads. People untorque those and lose the headspace. Much more important.

Thanks for that! I always figured the "3 time torque" existed before you entered the game, I had no idea that you were the one that put it in the manual. Also, I always thought the "3 times torque" was less important for used parts and only really needed for new parts... Well, I can safely say that I learned something today!

So what do early manuals like CM 102 say about barrel install if anything? I found a copy of the 68 one and the difference it had.

Also the three times torque is in a Colt manual and seems to say it is done to seat the nut to prevent loosening.

So would you recommend always starting at 20 foot pounds to hopefully work your way up to alignment within the low end of the torque spec? Or would you still recommend starting at 30? It's been a few years since you put that in the manual so maybe your opinion has changed?