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Discussion Starter #1
Has anyone pinned a factory 14" barrel assembly to 16" and if so what brake or flash hider did you use?

I was looking at where the barrel ends in the extension and it appears as though the factory supplied FH would come up a little short of the 16" mark...
 

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I think the AAC 3 prong flash hider are a bit longer. If you go to their web sight it will tell you what it will add in length.
 

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Discussion Starter #3
I checked them first because I have an M4-2000, but I think they all add between 1.7 to 1.8. Most will work with a 14.5" barrel but the SCAR barrel is obviously shorter... :sad:
 

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I had a 14'' hoping the aac miter mount pinned would get it to 16'' but it was 3/8 of an inch off, So I just filed a form 1. How the NFA measures is they stick a rod down the barrel until it hits the bolt face. so don't measure from barrel to breach!!!
 

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Discussion Starter #5
I have a 16s in Black and FDE and I only really wanted to SBR one of them... I've been trying to find a decent looking/performing FH or brake to avoid filing more paperwork. If I can't find a solution I'll probably just cut a 16" barrel to 14.5...
 

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Since you have two... I would keep one stock and cut the other 14.5pin or sbr, I would personaly sbr so you can have it 14", 10", whatever. Only reason I bought barrel assembally was to mitigate wear over the years and who knows they might not be around forever...
 

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Discussion Starter #7
My stamp should be here by next month, and I plan on primarily utilizing the 10" barrel on it because I carry it at work. I have both factory barrel assemblies waiting for it and the stock barrel still in place. I prefer less skinny barrel hanging out and I don't want to add extra weight with an extended hand guard because I have enough on the rifle already. I'm hoping losing a little barrel will lighten it up.
 

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Discussion Starter #9
I'd say about a 1/4 of an inch... If you measure from the end of the barrel extension to the tip of the FH it's 16 1/2" roughly, but if you measure the barrel itself it's recessed in the barrel extension approximately 3/4 of an inch.
 

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ATF measures from the base of a closed bolt to the tip of the flash-hider. So if you want to know for sure, grab the SCAR bolt and stick a cleaning rod and measure. I've always heard that the 14" with ECP flash hider would work but that would suck if it didn't because I wanted to do this as well.

http://www.atf.gov/files/publications/download/p/atf-p-5320-8/atf-p-5320-8-chapter-2.pdf

The ATF procedure for measuring barrel length is to measure from the closed bolt (or breech-face) to
the furthermost end of the barrel or permanently attached muzzle device. Permanent methods of
attachment include full-fusion gas or electric steel-seam welding, high-temperature (1100°F) silver
soldering, or blind pinning with the pin head welded over. Barrels are measured by inserting a dowel rod
into the barrel until the rod stops against the bolt or breech-face. The rod is then marked at the
furthermost end of the barrel or permanently attached muzzle device, withdrawn from the barrel, and
measured.
 

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Has anyone pinned a factory 14" barrel assembly to 16" and if so what brake or flash hider did you use?

I was looking at where the barrel ends in the extension and it appears as though the factory supplied FH would come up a little short of the 16" mark...
This is my plan, just gotta get the barrel! I will be using the BE Meyers flash hider. B.E. Meyers: Flash Hider for 5.56 mm Weapons
this hider brings 13.7" inch barrels to 16"...
 

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I wonder if an AAC brake would work instead of a flash hider? haven't checked their website to double check on if theres a length difference, but going off of memory I do believe the brake is a shade longer than the flashhider
 

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Discussion Starter #15
I think it would be close with any of the AAC's, but if my stamp ever arrives i'll report back. Unless someone else chimes in first. I think there are a few guys running 14" barrels on their SBR's around here?
 

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Silencerco makes a threaded .22 supressor spacer that screws on and gives the perfect amount of extension to make 16.1, no concerns about concentricity because it was made with suppressor use in mind.

It also fits inside the groove on the back of the AAC perfectly.
 

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Discussion Starter #18
Incase anyone is interested I measured my factory 14" barrel utilizing a rod down the bore to a closed bolt and it measured 16.1" with the factory 3 prong flash hider that comes stock on the assemblies... I might send this one off and get it pinned for a future build.
 

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is there any hoops you have to jump through to get the 14" barrel or is it ok to have unless its put on the rifle?
 

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Can any of you advise if the standard 14" barrel from FN with any of the AAC 51T hiders or brakes being pinned on make the legal length requirement? Thanks..
 
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