Does type of Barrel Nut = Better Accuracy?

AR/M4 AR Technical Discussion
1

I have a DD-9081 16" Govt Profile Mid-Length barrel. Looking to buy hand guards for the build.
I have a few questions regarding barrel nuts/free floating.
Does a hand guard that uses a integral barrel nut ie Noveske NSR/Daniel Defence modular add more rigidity and accuracy to the barrel, When compared to a Troy alpha rail that uses a standard barrel nut?
Is an upper that uses a low profile gas block and free floated hand guard more accurate than an upper that is free floated but has a FSB?

Thanks In Advance,
MickeyJr308.

2

The differences you’re talking about are negligible in comparison to the inherent accuracy of the barrel. Shoot… Pappabear has a 20 Colt Chrome lined Match Hbar with no FF at all. That sucker is amazing with irons. Put a magnified optic on it, and it’s hang with the finest FF guns all day long.

3

Agreed, Mark.

OP, for issues surrounding the barrel nut, I’d imagine the overall torque placed on the barrel nut would have more of an effect on accuracy than the type of nut used. It seems that, as far as the nut’s primary purpose, which is securing the shoulder of the barrel extension to the front face of the receiver, the type of nut would not have an enormous affect on the barrel.

I DO know that an overtorqued barrel nut (something toward the upper-end of the 30 to 80ft/lb window) can have a negative effect on accuracy.

I’m not saying that a barrel nut like the Geissele nut isn’t of superior design to the original Stoner design or that it can’t contribute to a quality rifle (though I’m FAR from an SME on AR accuracy).

4

Whether a free-floated barrel’s gas block has a sight as part of its design is pretty irrelevant. If you start tugging a sling attached to the FSB, free-floated or not, it will pull the barrel and affect where bullets hit.

5

The primary reason for proprietary barrel nuts is to support the mounting system for the rail not for accuracy improvement purposes per se. The rail is effectively a long aluminum lever attached to the upper receiver by the barrel nut. Geissele states in one his videos that he designed his barrel nut to provide additional bearing surface to ensure strength/rigidity for the rail versus the standard mil barrel nut If you compare the Geissele barrel nut to a standard mil barrel nut the difference is striking. I imagine other rail manufacturers with proprietary barrel nuts were driven by a similar rationale.

6

The two biggest things that negatively affect accuracy (besides the barrel itself) is the over torquing of the barrel nut, flash hider/MB and poor crown on the barrel
. If you want less flex in your rail, use one that has a longer barrel nut (like the Geissele, Noveske NSR, BCM KMR, etc).

When I build precision gun, I choose rails that only require 40ft LBS on the barrel and time my FH/MB. I will also true up the barrel and put a 11 degree crown on it.

YMMV.

C4

7

Grant, what part if the barrel are you true. I’ve seen people true the barrel extension to the receiver and also the end of the barrel

Using Tapatalk

8

Was going to ask how can you tell if you over torqued your Flash hider? How do you “time” it?

9

Muzzle.

C4

10

You can buy a torque wrench and don’t go over a certain value OR always have bottom of the FH/MB at or around the 4 o’clock position.

I use timing washers that are in different thicknesses to get the FH/MB where I want it.

C4

11

Thanks everyone for the great information, I think I will be buying a Noveske NSR rail, The gieselle mk2 rail looks good but seems a little heavy.

Merry Christmas,
MickeyJr308.

12

Nice choice. Looks like you are going top notch on your upper :slight_smile:

13

I didn’t know this. Why not have it at the 6 o’clock?

14

You always want the FH/MB to end (and be tight) when you get to the 6 o’clock position. If you have ever installed a SureFire Adopter, you will know what I am talking about.

C4