Working on building a Centurion Arms rifle and need a barrel. A Centurion barrel is what I want but they are rarer than hen’s teeth. I’ll settle for one from a quality manufacturer like BCM, Noveske, FN, DD etc., but it HAS to be midlength gas and HAS have a FSB. I’ll take a 16" or a 14.5" pin/weld with a barrel nut already installed. I would also prefer it to be phosphate coated rather than nitride.