Hello:
I have a Bushmaster A2 Upper with no Flash hider on the front of the barrel.  Its 16 inches long, and is a very heavy barrel mounted to the upper.   Its almost new, and its a heavy barrel.  It is a 1/9 twist.  Can I remove this barrel, and have a flash hider put on it, and can I put it into a A3 upper with the rail?  Or do any of you have any good suggestions on what I should do with this upper as its is just sitting in my closet.  

Thanks
BillWI

You could do that, or just sell the entire upper on the EE and start from scratch.

adcofirearms can thread your barrel for a flashider and the upper reciever is simple to replace with the step-by-step instuctions located in the build it yourself forum.