Did some diggin on ar15.com found this. The list from the FAQ I am (stalled) working on... LMT = LMT, Lauer, DS Arms, PWA, Eagle, Knights Armament, Barrett, Bushmaster (?) CMT = Stag, RRA, High Standard, Noveske, (new) Century, Global Tactical, CLE, S&W, MGI, Wilson Tactical, (some) Colt, Ratworx LAR = Grizzly, Bushmaster (L Prefix), Ameetech, DPMS, CMMG, Double Star, Fulton JVP = Double Star, LRB MMS = Mega, GSE, Dalphon, (old) POF, Alexander Arms, Olympic = Olypmic, SGW, Tromix, Palmetto, Dalphon, Frankford, (old) Century Sun Devil = Sun Devil forged billet receivers Superior = Superior Arms Grenadier Precision POF Forged Billet DPMS = Panther .308, Fulton .308