Importance of barrel extension fit to receiver?

[STI_1911_Guy]

I have been looking up ways to "accurize" an AR-15 and one of the more common things that pop up is the barrel extension to receiver fit. I seen where people loctite the extension into the receiver and where people use shim stock wrapped around the extension to tighten up the fit. I was wondering if this would help to increase accuracy and which ways some of the fellow hide members have used with success. Thanks.

 

[nicholst55]

Re: Importance of barrel extension fit to receiver?

Some diehard High Power shooters actually epoxy the barrel extension to the upper. I'm not sure I'd go quite that far, but, you get the idea.

 

[LoneWolfUSMC]

Re: Importance of barrel extension fit to receiver?

I recently had a Geoff Corn re-crown the barrel on my AR10. When he reinstalled it he used wheel bearing adhesive, but he said blue loctite works just as well. The goal is to prevent any movement of the barrel in the upper.

Just to be clear, this is ONLY on the extension to upper surface. They threads still get moly grease.

Geoff also sealed up the gas block to barrel and gas block to tube connections.

Combined with the re-crown I saw my group sizes shrink by half. Now if I could just find a cure for the "first round flyer" from the magazine I would be satisfied with this rifle.

I will be using the loctite trick on all my precision AR's from now on.

 

[AXEMAN]

Re: Importance of barrel extension fit to receiver?

nice info lonewolf. makes sense. you gotta figure it all may seal on its own with carbon build up eventually. did he use the same adheasive to seal the block/tube areas?

 

[RuLins05]

Re: Importance of barrel extension fit to receiver?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LoneWolfUSMC</div><div class="ubbcode-body">I recently had a Geoff Corn re-crown the barrel on my AR10. When he reinstalled it he used wheel bearing adhesive, but he said blue loctite works just as well. The goal is to prevent any movement of the barrel in the upper.

Just to be clear, this is ONLY on the extension to upper surface. They threads still get moly grease.

Geoff also sealed up the gas block to barrel and gas block to tube connections.


Combined with the re-crown I saw my group sizes shrink by half. Now if I could just find a cure for the "first round flyer" from the magazine I would be satisfied with this rifle.

I will be using the loctite trick on all my precision AR's from now on. </div></div>

Are you putting the magazine in with the bolt open? If so don't. Insert the mag with the bolt closed and use the charging handle. Not exactly the same but closer.

 

[Hellbender]

Re: Importance of barrel extension fit to receiver?

This explains how to do it right, but the locktight is OK, (not as good, but better than nothing)

http://www.snipershide.com/forum/ubbthre...928#Post2101928

RuLins05....

It will give more 1st round consistency by locking the bolt to the rear and using the release button.

The charging handle adds friction to the closing cycle.

LoneWolfUSMC...

Slicking everything up as explained in my Ultimate AR series of posts will cure (or reduce) the 1st round flier.

Don't neglect the mags, either.

 

[KevinB-KAC]

Re: Importance of barrel extension fit to receiver?

The other issue is if the end of the receiver is true so the barrel extension indexes on it flat (also needs the barrel extension to be true and flat).

This is one reason some guns exhibit shift when warming up.