Who provides the 16” .223 Wylie barrel on the complete aero fde upper? — 1 Answer

Technically speaking Aero Precision provides the barrels used in their rifles even though they are manufactured by Ballistic Advantage in their facility in Florida.
To expand on that technicality the story goes; in December 2014, Aero Precision acquired a majority stake in Ballistic Advantage, making BA a subsidiary company of Aero Precision.
While they operate as two separate and distinct brands with their own identities, Ballistic Advantage functions as the barrel manufacturing arm of Aero Precision. Outside of the barrels, Ballistic Advantage branded products are manufactured by Aero Precision in their Manufacturing Facility in Washington State.