"Death From Above"
I have a post ban non threaded KBI BBL with just shy of 1500 rounds down the tube. I built this on an A2 upper. My intention is to send it off to Compass Lake Engineering to thread the end of the bbl for a flash hider(no longer in NY thank god) and use the bbl to build a scoped flattop upper. Here is my conundrum, I will have to have the rifle extension changed to an M4 extension and I think this has the potential to change the headspace. I have a brand new KBI bbl with an M4 extension. Do I just put the A2 upper back together and sell it and use the new bbl to build the new match rifle.