The .223 version is chambered with a Wylde-type chamber. These barrels are threaded for and furnished with a pinned barrel extension with proper head space and the gas port hole drilled and an 11º target crown. We are milling a narrow flat on the bottom side of the gas port section for set screws used with some types of gas blocks. This prevents marring of the .750″ or .936″ diameter by the set screws and helps align the gas block with the gas port hole.
All current production drop-in barrels use an M4 style barrel extension.
The front section of the barrel is engraved with “Lilja AR .223 8T”. Just add your gas block and tube and drop into your upper receiver.