Question , Does anyone know if it is legal to mount a "old style" 3 pronge flashhider on a post ban AR15 ?   The mounting would be by threading the muzzle , then welding on the flashhider to make it unremoveable. Also does the 3 pronge flashhider meet the silly gernade lancher (22mm) rule ?

If that old 3 prong flashhider reduces muzzle flash then it would be illegal regardless how its attached.

a 3 prong woudmnt count as a grande launcher so if u welded it on and REMOVED the pistol grip there for having the Flash hider as your one fetire u would be ok
or just simply make the magazine non detachable

If you remove the pistol grip and have the flash hider as your ONE allowable feature, it doesn't have to be welded.  Flash hider and threads for a flash hider count as the same item.

However, the 3-prong design is still 22mm diameter, so would probably count as a grenade launcher - you'd have to weld a tab to the flash hider to prevent its use as a "grenade launcher".'

You may want to check with BATF for other acceptable ways to prevent a muzzle device from being classified as a grenade launcher, too.

is anyone else feeling dizzy?[puke]

(rhetorical question, but answer if you must)why make laws that an average person cannot understand? i once had a liberal tell me that guns were unregulated. after i went HA in his face, i proceeded to explain all that i knew. he ran out of patience before i ran out of wind.
-rant over-

Legally speaking. NO!!

Thanks for all replys , I think I will keep the pistol grip on and the mag detachable.          After giving this a lot :) of thought all I can say is BULLSH*T !!