Im looking to buy a 14.5" barrel and add a flash suppresor making the barrel 16". Does it absolutly have to be pinned and welded or can it be loc-tited???

QFT - don't play around.

Welded or silver soldered.  Loc-tite isn't sufficiently permanent.

You don't have to order it already permanently attached to a muzzle device, but it does require pin and welding or silver solder to be legal.  Finalize your handguard and FSB before that, and you'll be happy.

What do you mean by "Dont play around?"

What he means is that unless you use one of the ATF approved methods of permanently installing the device (and loc tite isn't one of them), you are looking at serious prison time.



 

Any idea where I can find the "approved methods" in legal writing?

Yeah...don't do it one of the ways that has already been suggested and it will be on your indictment.

http://www-2.cs.cmu.edu/afs/cs/usr/wbardwel/public/nfalist/atf_letter40.txt

From page 6 of the National Firearms Act handbook.
http://www.atf.gov/firearms/nfa/nfa_handbook/index.htm
CHAPTER 2. WHAT ARE “FIREARMS” UNDER THE NFA?
Section 2.1 Types of NFA firearms
2.1.3 Rifle. A rifle is a firearm designed to be fired from the shoulder and designed to use the energy of



an explosive in a fixed cartridge to fire only a single projectile through a rifled barrel for each single pull



of the trigger.11 A rifle subject to the NFA has a barrel or barrels of less than 16 inches in length.
The length of the majority of rifle barrels is measured from the muzzle of the barrel to the face of the



closed breech on a line parallel to the axis of the bore. In the case of a rifle having a chamber(s) not an



integral part of the barrel, such as a revolving rifle, the barrel length is measured from the muzzle to the



front of the separate cylinder and does not include the chamber. NOTE: Any muzzle attachment such as



a flash suppressor, compensator, muzzle break, etc., is not included in the barrel length measurement



unless the attachment is permanently affixed to the barrel. Acceptable methods for permanently



attaching a device to a rifle barrel are deep penetrating, full fusion, gas or electric steel seam welds of



high temperature silver solder. Depending on the dimensions of a particular barrel it may also be



possible to permanently affix a muzzle attachment by drilling a blind hole through the attachment and



into the barrel wall. A steel pin that is flush with or below the outside diameter of the attachment is then



inserted and the hole welded closed.