I have purchased a pre ban 16 inch upper with a carry handle.  There is no bayonet lug up front but it does have a threaded barrel with a hinder on it.  If I take off the hinder and attach a muzzel break will this make it post ban legal ?  If so can anyone point me to a location to purchase a break that will work with the threaded barrel.  Thanks fo rhte newbie help.

I'm almost certain that it would have to be permenantly attached.

You cannot have a threaded muzzle on a post ban barrel that can accept a flas supressor/grenade launcher.  Your 2 choices are to have a BATFE approved muzzle device (compensator/brake) premenantly attatched (pinned & welded) or have the muzzle crowned so that there are no threads.

Vinnie is correct. I had a Cav Comp brake pinned & welded by K2 sports. Its looks very nice, however is too loud and the blast obscures the sight picture, I would recommend a fake flash hider by KKF, that way you get the look, but not the noise and blast. It will also serve as a functional muzzle protector.

Kurts A3 fake flash hider is very nice...see below:
[img]http://www.kurtskustomfirearms.citymax.com/i/section_10746/A3FFSMS.jpg[/img]

his website is:[url]http://www.kurtskustomfirearms.citymax.com/page/page/8932.htm[/url]
Most people I know that have bought products/services from him rave about Kurt's work.
he does have an A3 tac brake, if you want a muzzle brake, although the tiny amount of recoil on the AR15 doesn't warrant it IMHO.

NOTE: Although this method requires destruction of the muzzle device to remove it, the barrel threads can remain intact after removal, that way if the AWB sunsets, you can remove it and put on a proper flash hider. However, this method (threading, pinning & welding)is considered permanent by the BATF if done correctly since it requires tools & gunsmithing to remove.

As always thanks for the helpful information !