The Daniel Defense MK18 Upper Receiver is a complete upper receiver system ideal for placement on AR pistol lower receivers or AR rifle lower receivers (NFA Short Barreled Rifle Regulations Apply). The upper is built around a carbine-length direct impingement gas system and a 10.3″ barrel chambered for 5.56 NATO. The MK18 Upper features Daniel Defense’s RIS II Rail System with Santoprene heat resistant rail panels. Components of the Daniel Defense MK18 Upper ReceiverGas System: Low Profile 4140 Steel Gas Block, Carbine-Length, Direct Impingement Barrel: 10.3″ Cold Hammer Forged Chrome Moly Vanadium Steel with 1:7″ Twist Muzzle Device: 17-4 PH Steel Daniel Defense Flash Suppressor with Salt Bath Nitride FinishBolt Carrier Group: MIL-SPEC M16 Profile Chrome LinedHandguard: 6061-T6 Aluminum Daniel Defense RIS II Rail System with Rail Panels. DEMO Daniel Defense MK18 Black 5.56 NATO 10.3″ Short Bbl Upper Receiver Group 23-004-08013-006 – Excellent Condition USED9762
Geissele Automatics Geissele Super Duty 5.56mm 16" Heavy Bbl (.750 Journal) Black Stripped Upper Receiver (No Charging Handle, Muzzle Device, or BCG) Original price was: $1,025.00.$899.99Current price is: $899.99. 
Mitchell Defense The DOC AR-15 .300 BLK 10.3in Upper Receiver Chrome-Moly Barrel Black Finish M-LOK Free-Float Handguard Original price was: $1,290.00.$1,225.50Current price is: $1,225.50. 
DEMO Daniel Defense MK18 Black 5.56 NATO 10.3″ Short Bbl Upper Receiver Group 23-004-08013-006 – Excellent Condition USED9762
Original price was: $1,517.00.$1,100.00Current price is: $1,100.00.
