I have a used RRA middy barrel that came off a customers rifle. It has less than 200 rounds thru it and is in just about perfect condition. It has no bayo lug and is not threaded. It has a plain muzzle and is not chrome lined. No gas tube, no delta assy, barrel only.
ETA: It has a FSB. It has not been removed so the pins are not buggered at all.
$125 shipped obo.