I have seen in several catalogs (BM, etc.) that you may place a pinned on muzzle brake on a 14.5" barrel and be legal.  However, I like the cleaner lines of the straight threaded Mini Y comp that BM offers.  Am I allowed to take a postban 14.5" barrel, thread it for the Mini Y, and then weld the brake in place, for a legal length of 16"?

Thanks,

Pugsley

Yes.  The currently acceptable methods (to the ATF) of fixing a threaded brake on a post ban are to either:

install the brake, drill for a pin or setscrew, install the pin or setscrew and weld the pin or setscrew into place, or;

install the brake and silver solder it to the barrel over 50% of its circumference.

You don't have to thread a post ban barrel, it's also acceptable to use a threaded pre-ban barrel and cut or grind off the bayonet lug, then fix the brake in place as described above.  

It's probably easier to grind off a bayonet lug than to thread a barrel for most do-it-yourselfers.

I believe you have to use the 1100 degree melting point silver solder to be legal with that method.

That is my understanding as well.

Thank you,

My intentions are (as long as I am legal) to silver solder the threaded brake in place, or pin or both.  If pinned, I will have the pin ground flush with the brake, so as to leave the cleanest lines possible on final installation.

I was thinking about trying to pin and weld my own brake on, then realized that I would destroy the temper on my barrel trying to do it myself.  Unless you have the proper equipment and training, I would reccomend sending your barrel to a qualified gunsmith and let them do it.  KKF, Wilson, and Gunsmoke Enterprises seem to be the top three choices for a brake that looks like the A2 birdcage.  Mine is currently with Ed at Gunsmoke having one of his brakes installed.  I'll let you know what it looks like and how it functions when it comes back.