Yes and maybe... When the brake was attached the barrel was threaded, then a hole drilled, a dowel pin inserted, then the pin hole was welded over. Depending on the skill/luck/method used on removing the brake will depend on whether or not you'll still have threads for installing a flash hider if/when the AWB expires. If you can locate the pin and drill it out (without drilling through the barrel and rifling or breaking off the drill bit in the brake
) then you may just need to clean up the threads a bit. If you chop off the end of the barrel with the brake
, then the barrel would need to be recrowned and threaded to install a flash hider (naturally). If you chose to grind off the brake where the weld is, then depending on your skill/luck/patience will determine how much work would be needed to install the A-2 flash hider.
PS. I hope that this makes sense, I'll re-read this post after I get some rest and fix any mistakes that I made. I just walked in the door from driving back from Reno and am a bit fatigued