If the barrel is 14.5 inches it is most likely welded to make the overall length 16 inches. You can see the spots where it is welded if you look very closely. If the barrel is 16 or more inches the brake should not be welded. There have been cases where barrels were specially made for a state that doesn't allow threaded barrels. If this is the case it would have a brake welded on and not a flash hider. It would also have the bayonet lug milled off.