Barrel Nut Problem on an AR15

[Hawk]

I purchased a Trinity Force hand guard to build an upper using my Rock River varmint barrel and a Rock
River upper.
The barrel nut uses a crows foot wrench instead of the standard barrel nut wrench.
The problem is, the barrel nut only has a clearance of 1.000" diameter and the RR barrel in 1.055" diameter past the gas block. The nut won't go over the barrel. I called TF and they have no solution or answers.


Two questions:
1. Do you think I could remove 0.06" with a dowel and emery cloth or wet/dry sandpaper fairly easily?
2. The barrel nut is steel and I will be removing the surface coating. How do I protect the inside of the nut from rust after remove of the 0.06" of metal? Grease, Oil, Recoat with something else or is it even an issue?

Just don't want to start and eliminate the possibility of a returning the hand guard without knowing I can do it.

 

[Ian]

I wouldn't have called Trinity Force, I would have called RR and asked WTH. A factory barrel nut runs about 1.010" on the flange.

 

[fiver]

if RR is making a barrel that big they must have a solution to putting a hand guard around it.
I'd give them a ring and see what they are doing.
then you could send the other stuff back if necessary.

I get so wound up about stuff like this.
I wanna do some changes to a couple of my AR's but with everybody making everything I just know I'm gonna run into this same thing.
and to me it's like rem/win screwing up 30-30 ammo it just shouldn't be possible.

 

[Ian]

I run into the same problem building ARs. The industry standards are pretty good, but far from perfect. Lots of cheapie handguard nuts are way loose on the receiver threads, BCG bores and magazine wells are all over the map on dimensions, and don't check headspace with hodge-podge components unless you want to be disappointed.

RRA most likely recommends their own barrel nut, but there's a note on some of their handguards that indicates "may require some gunsmithing". I'm going to say just file the nut and cold blue it. If you install the nut with EP moly grease (I use ARP stud mount equa-torque moly compound), plenty will get on the barrel nut flange and prevent rust for a very long time.

 

[Hawk]

The original action came with a Hogue free float hand guard, but I had to destroy the barrel nut getting it off.
Doesn't take a barrel wrench. Had to use a strap wrench and broke two before it came loose with the third wrench.
Don't know how much torque it had on it, but it was a lot. By then, the nut was so out of round, the barrel of the hand guard wouldn't fit it anymore.
I'm pretty handy, but I couldn't get it back together. The threads were too fine and stripped out trying to reassemble it.
I'll never buy a Hogue.

 

[Ian]

Hogue handguards suck rocks, good call on ditching it. You should see the stupid plastic tool that you're supposed to use to torque the nut. I guarantee if you didn't take it off by hand that whoever installed it didn't use the tool it came with. I installed one for my boss and had to go make some hardwood blocks to clamp around the nut so I could put a pipe wrench on it. And they're ridiculously heavy.

 

[Hawk]

Wow. Underestimated what it would take to open the nut up.
Using emery cloth and a tight fitting wooden dowel chucked up in a drill. An hours worth of work with the drill and I've only opened it up about 0.012" and I need 0.06".
Must be made out of some sort of meteorite or alien metal!!

 

[Hawk]

I've gone to 60 grit wet/dry sand paper and it's not working any bettter.

 

[358156 hp]

Try a grinding bit for a Dremel in your drill.

 

[quicksylver]

A sanding drum in the drill press...they make small ones..