| Platform | Mk4 |
| Caliber | 5.56x45mm |
| Operating System | Direct Impingement |
| Barrel Length | 18 |
| Barrel Twist | 1:7 |
| Barrel Contour | MT |
| Barrel Material | 416SS, SBN |
| Barrel Twist | 1:7 |
| Muzzle Device | CMMG ZEROED Muzzle Brake |
| Muzzle Thread | 1/2 x 28 |
| Gas Port Location | Rifle |
| Gas Block | 0.750 Non-Adjustable |
| Upper Receiver | Billet 6061 T6 Aluminum |
| Lower Receiver | Mk4 Forged 7075 T6 Aluminum |
| Hand Guard | CMMG EML15 M-LOK |
| Finish | Cerakote |
| Charging Handle | CMMG ZEROED Ambi |
| Pistol Grip | CMMG ZEROED Pistol Grip |
| Buffer Type | Rifle/A1, AR15 |
| Receiver Extension | A1 |
| Stock / Brace | Magpul MOE Rifle Stock |
| Trigger Type | ZEROED Drop-In |
| Trigger Guard | CMMG ZEROED Trigger Guard |
| Safety Selector | CMMG ZEROED 60/90 Degree |
| Magazine | Magpul 30rd PMAG |
| Weight | 7 lbs |
| Length | 37.8" |
Please Allow 15-30 Days To Process Your Order.
State/local restrictions may apply in CA, CO, CT, DE, DC, HI, IL, MD, MA, MI, NJ, NY, or WA. Customers must review our Firearms Shipping Policy prior to ordering.
Firearms with attached pistol brace. Please confirm your FFL is accepting transfers for pistol brace equipped firearms prior to ordering.
ENDEAVOR, Mk4, 5.56mm, 18"
There’s a world of options when it comes to AR15s, and for those that want to reach out to further targets or hunt with 5.56, the 18-inch ENDEAVOR® Mk4 chambered in 5.56x45mm is an awesome choice. Despite all the different caliber offerings available today for AR15 pattern rifles, 5.56x45mm still stands as one of the most popular.
Built on our Mk4 – AR15 platform, this ENDEAVOR can make use of just about any AR15 compatible component, and utilizes a nitride-finished 18-inch 416 stainless steel barrel for enhanced ballistic performance.
Each CMMG® ENDEAVOR rifle is purpose-built for long-range performance, with everything from the Magpul® MOE® rifle stock to the ZEROED™ muzzle brake, and every part in between selected for its utility to the avid marksman.
The EML™ 15 handguard maximizes customization potential. M-LOK® attachment slots at the 12, 3, 6, and 9 o’clock positions give you plenty of real estate to mount accessories, while the Picatinny rail sections allow for easy and solid mounting points for sights and accessories.
ZEROED parts and accessories – Quality comes standard
The AR15 platform is well known for its capability for customization but picking the right parts doesn’t have to be a nightmare of homework. CMMG’s ZEROED parts and accessories are made here in the USA with quality and attention to detail that is second to none and each ENDEAVOR comes equipped with a slew of ZEROED parts standard, including:
ZEROED AR15 Ambi Charging Handle
ZEROED Extended Mag Release Button
ZEROED AR15 Polymer Dust Cover
Lifetime Quality Guarantee
We aim to please, that’s why every CMMG product is backed by our Lifetime Quality Guarantee against material and workmanship defects. Learn More.
~Firearms shipping to states with magazine capacity restrictions will only ship with 10rd magazines in place of standard capacity magazines. CMMG does not address any other state compliancy requirements for further restricted states.