Mk4 T
CMMG Inc. · Carbine · In Production · 2014
Also known as: CMMG Mk4 Tactical, Mk4T
Overview
The CMMG Mk4 T is a value-oriented AR-15 style semi-automatic rifle chambered in 5.56x45mm NATO, introduced in 2014 as part of CMMG's Mk4 platform expansion. Manufactured by CMMG Inc. in Boonville, Missouri, the Mk4 T emphasizes affordability and reliability without sacrificing essential features. The rifle features a 16-inch medium-weight tapered barrel, forged 7075-T6 aluminum M4 upper and AR-15 lower receivers, and an RKM11 KeyMod free-floating handguard with top-mounted Picatinny rail. KeyMod attachment points at 3, 6, and 9 o'clock positions provide a lightweight, low-profile alternative to full-length Picatinny rails. Standard furniture includes an A2 pistol grip and M4 buttstock with 6-position mil-spec receiver extension. Weighing just 6.3 pounds unloaded and measuring 32 inches with stock collapsed, the Mk4 T offers excellent maneuverability. CMMG's single-stage mil-spec trigger provides consistent performance, while the forged receivers ensure durability. The Mk4 T represents CMMG's mission to provide quality AR-15s at accessible price points for law enforcement, competitive shooters, and recreational users.
Specifications
| Weight (empty) | 2858 g (100.8 oz) |
| Weight (loaded) | 3298 g (116.3 oz) |
| Overall Length | 813 mm (32.01") |
| Barrel Length | 406 mm (15.98") |
| Action Type | Gas Operated Direct Impingement |
| Firing Mechanism | Hammer Fired |
| Trigger Type | Single Stage |
| Trigger Pull | 32 N (7.2 lbf) |
| Magazine Capacity | 30 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 905 m/s (2969 fps) |
| Muzzle Energy | 1640 J (1210 ft·lbf) |
| Effective Range | 500 m (547 yd) |
| Maximum Range | 3600 m (3937 yd) |
| Barrel Rifling | Right Hand |
| Rifling Twist | 229 mm (9.02") |
| Number of Grooves | 6 |
| Frame Material | Aluminum Alloy |
| Barrel Material | Steel |
| Stock Material | Polymer |
| Finish | Hard Anodized |
Calibers
- 5.56x45mm NATO · primary · 5.56x45mm NATO — also known as 5.56mm NATO, 5.56x45mm, .223 Remington
Features
- Firing modes: Semi Automatic
- Feed systems: Detachable Box Magazine
- Safety mechanisms: Manual Safety Selector
- Features: Free Float Handguard, Keymod Mounting, Medium Weight Barrel, Collapsible Stock, Accessory Rail, Forward Assist, Dust Cover, Flat Top Receiver, Picatinny Rail, A2 Pistol Grip, M4 Stock
Variants
- Mk4 T .300 Blackout — Caliber Variant
- Mk4 T 9mm — Pistol Caliber
- Mk4 T .22 LR — Rimfire
- Mk4 RCE (RECCE) — Precision
Service history
Operators
- United States Law Enforcement · as Mk4
- Civilian Sport Shooters
Production
Production years: 2014-present
Exact production numbers not disclosed by CMMG. The Mk4 platform remains in active production with multiple variants.
Origin
Country of origin: United States
Designer: Eugene Stoner
Notes
CMMG Inc. was founded in 2002 in Fayette, Missouri, by John, Jeff, Gretchen, and Stephanie Overstreet, initially focusing on AR-15 lower receivers. The company name stands for 'Central Missouri Machine Guns.' In 2016, CMMG relocated to a larger facility in Boonville, Missouri (the Overstreet brothers' childhood home), to address growth constraints. The Mk4 platform designation indicates CMMG's AR-15 format rifles, distinguishing them from the larger Mk3 (AR-10 format) and smaller Mk9/Mk10 (pistol-caliber) platforms. The 'T' designation in Mk4 T likely indicates 'Tactical,' though CMMG has not officially clarified this. The Mk4 T's 1:9 twist rate is optimized for 55-62 grain ammunition, making it suitable for training and recreational shooting with standard .223/5.56 loads. CMMG offers the Mk4 T in multiple calibers including .300 AAC Blackout, 9mm, and .22 Long Rifle, utilizing the same core platform with caliber-specific modifications. KeyMod attachment system predates M-LOK and offers similar benefits-reduced weight compared to full Picatinny rails while maintaining accessory mounting capability. The Mk4 T competes directly with budget-friendly offerings from Smith & Wesson, Ruger, and Palmetto State Armory, emphasizing value and American manufacturing. CMMG's dedication to customer service and quality control has earned strong reputation despite lower brand recognition compared to major manufacturers.
Background
Born in the heart of Missouri by a family-run operation, the CMMG Mk4 T represents the American firearms industry's grassroots spirit-no government contracts, no military heritage, just the Overstreet family's commitment to building affordable, reliable AR-15s that everyday shooters could trust. When CMMG announced the Mk4 T in 2014, they weren't trying to revolutionize the AR-15; they were simply proving that quality didn't have to come with a premium price tag.