Just called up Bushmaster to see if they had any 20" gov't profile barrels with the 1/7 twist. They did so I ordered a new A3 upper, I'll call it a USMC b'day present to myself. I originally ordered it with the detachable carry handle then realized that I really wanted an A.R.M.S. # 40 instead so I called them back and switched it.
Now to wait for the next paycheck to see if I can get some of that 5.56 NATO from GPSS if it's not to late.
Thanks for the sound off space.