O00319.204 Ruger EngravingThreading

.204 Ruger 11-Twist M4


M4: .975″ diameter for 2″ then a radius down to .850″ diameter to the .750″ diameter gas block section. From the gas block to the muzzle the diameter is .725″. Barrel length is 17″ including the M4-type barrel extension and the M4 barrels are furnished with a .500″ x 28 TPI x .600″ long threaded muzzle. The gas system is carbine-length. This barrel profile is an exact copy of the Recon barrel we’ve made for the US Navy SEALS. Weight is 2.18 pounds. Engraved: Lilja AR .204 Ruger 11T”. To see a .pdf drawing of the profile – Click Here

In stock

Product Description

The .204 Ruger is chambered with a semi-auto match-type chamber. These barrels are threaded for and furnished with a pinned barrel extension with proper headspace 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. To see additional information concerning the .204 Ruger cartridge and functioning in AR’s – Click Here

All current production drop-in barrels use an M4 style barrel extension.

The front section of the barrel is engraved with “Lilja .204 Ruger 11T”. Just add your gas block and tube and drop into your upper receiver.


This image shows the three AR-type contours that we are keeping in-stock as a drop-in type barrel (muzzle threading is standard but not shown in image). The top contour is our AR24 contour, the middle one is our AR740 with the Wasp weight reduction section turned on the .975″ diameter. The bottom contour is the carbine length gas system M-4.


Additional Information

Weight 4 lbs
Dimensions 24 x 1.5 x 1.5 in