The Oly Arms pistol caliber carriers use alot of the 5.56/.223 specs but are completely different. That is to say 5.56/.223 and pistol cal carriers use different blueprints and are made on different cnc machines. New production pistol cal carriers also do not have forward assist notches. Older ones did, most likely made "out of house", I have one of the older ones in my 45 ACP carbine.
Oly Arms used to buy their carriers "out of house", they now make them all "in house", 5.56/.223 carriers and bolts are both produced on new state of the art Morei Seiki CNC machines. One Morei for bolts one for carriers, the carrier machine is so state of the art it can run (sic) itself with no operator. Pistol cal carriers and bolts are still made on "old fashioned" CNC Fadals and Maho's that cannot run themselves.
Bottom line is that .223/5.56 and pistol cal carriers and bolts are alot different, although older examples of the pistol cals were probally made from .223/5.56 carriers.
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