The Noveske 16 inch 300 AAC Blackout - Noveske NSR 13.5 upper features a Noveske 16 inch 300 AAC Blackout, stainless barrel with 1:7 twist improved polygonal rifling, Noveske 300 Blackout match chamber, extended feed ramps, bead-blasted finish, pistol length gas system, pinned low-profile gas block, in a medium contour with a 5/8-24 threaded muzzle.  Built on a Vltor MUR-1A receiver with M4 feed ramps, Noveske 13.5 NSR Rail, and an A2 flash hider. 

These are assembled and test fired by PK Firearms.

The DPMS 18 inch SST Mini SASS - YHM 5005 - Smith Vortex upper features an 18 inch DPMS Mini SASS fluted, bull barrel, manufactured from 416 stainless steel with a black teflon coating, chambered in 5.56 NATO with a 1:8 twist rate, midlength gas system and a 1/2-28 threaded muzzle.  Built on an M4 ramped, mil-spec flat top receiver with a YHM 5005 rail, low profile gas block and a Smith Vortex flash hider.

These are assembled and test fired by PK Firearms.

The Yankee Hill Machine 16 inch Fluted - CAR Plastic Handguard - YHM-9394 Front Flip Sight upper features a Yankee Hill Machine 16 inch fluted barrel chambered in 5.56 NATO, with a 1:7 twist rate, carbine-length gas system and a 1/2-28 threaded muzzle.  Barrel has an M4 ramped extension, is manufactured from 4140 steel, heat treated to RC 25-32, and contains diamond fluting which improves rigidity and aids in barrel cooling.  Built on a milspec M4 ramped flat top receiver with a carbine length plastic handguard, YHM-9394 front flip sight and an A2 flash hider.

Daniel Defense 16 inch Cold Hammer Forged barrel with M4 ramped extension, manufactured from ordnance-grade 4150 Chrome Moly Vanadium  alloy steel for exceptional strength, and magnetic particle inspected (MPI) to ensure there are no internal flaws in the metal. Installed on a Milspec Flat Top receiver with 5.56 chrome lined bore and chamber, 1/7 twist, F marked front sight, A2 flash hider and a Magpul MOE Dark Earth carbine length handguard.  Available with Black, Dark Earth, or OD Green handguard.  Select color option at checkout.