If CMMG’s latest edition to its AR rifle lineup appears familiar, it should. The base components that go into the Mk4 T series are used in a majority of the Missouri manufacturer’s other AR rifles.
What is different in the line is the addition of the company’s new RKM11 KeyMod free-floating hand guard and a 1913 Picatinny upper rail.
The hand guard adds an element of versatility to the platform with KeyMod slots at the 3, 6 and 9 o’clock positions. The slots give a lower-profile mounting option compared to Picatinny rails. But if your are Picatinny dedicated the company offers five-slot adapter rails, attachable to any of the KeyMod slots.
There are four rifles available in the new AR rifle line, including 5.56×45 NATO, .300 AAC Blackout, 9mm and .22 long rifle.
The 5.56mm and .300 BLK models are offered with either a 416 stainless steel or a nitrided 4140 chrome-moly steel barrel in a medium taper profile. The 9mm and .22 LR versions come standard with the nitride 4140 chrome moly M4 profile barrel.
CMMG Mk4 T Specifications:
Caliber: 5.56x45mm NATO/.300 AAC Blackout/9mm/22 long rifle
Barrel: 16″ medium weight tapered profile (5.56mm, 300 BLK)
Muzzle: A2 Comp., Threaded ½-28 (5.56mm, 22LR), ½-36 (9mm), 5/8-24 (300 BLK)
Hand Guard: CMMG RKM11 KeyMod hand guard
Upper Receiver: Forged 7075-T6 AL M4
Lower Receiver: Forged 7075-T6 AL AR15
Trigger: Single stage mil-spec style trigger
Furniture: A2 pistol grip, M4 butt stock with 6-position mil-spec receiver extension
Weight: 6.3 pounds (unloaded)
Length: 32 inches (stock collapsed)
MSRP: 5.56mm/.330 BLK Bead Blasted 416 1:7 Twist Barrel, 30-roundd PMAG $1,049; 5.56mm SBN Nitrided 4140 CrMo 1:7″ Twist 30-rd PMAG $999.95; 9mm Nitrided 4140 CrMo 1:10″ Twist 32-rd $1,149.95; .22LR Nitrided 4140 CrMo 1:16″ Twist 25-rd R3 $899.95.
Recommended AR Resources
Gun Digest Shooter's Guide to the AR-15
The Gun Digest Book of the AR-15
Gunsmithing the AR-15 Volume 2