Rifle makers CMMG dropped the MkW Anvil into their mid-sized AR lineup. Its intent is to eat large calibers with large casings so it’s no surprise this rifle is chambered in .458 SOCOM.
Utilizing a SLR Rifleworks Sentry 7 adjustable gas block, shooters can dial in adjustments to fine tune accuracy with different .458 loads.
Forgoing a standard AR-15 sized bolt, which would require milling to handle a large diameter such as the .458, CMMG opted to utilize its powerboat design. This design eliminates the need for the AR-15 milled bolt, which would result in a thin and fragile bolt face, in favor of the AR-10 sized bolt with greater durability.
The MkW Anvil also favors the AR-10 body in addition to the bolt. Set upon an AR-10 platform, the upper receiver is shortened by three-quarters of an inch. This reduction in size aims to minimize weight and improve ergonomics. As it stands, the Anvil weighs in a 7.5 pounds unloaded on a 33.5-inch frame with collapsed stock. While the Anvil sits upon an AR-10 body, it still accepts standard AR-15 magazines which can hold approximately 10 rounds. The rifle does ship with a Lancer L5 magazine specifically designed for use with the .458 round though.
Chris Reinkemeyer, CEO of CMMG, said in a press release that the company is excited by the Anvil feedback from customers. “Our experiences with .458 SOCOM have been extremely positive in terms of accuracy and lethality on large sized game. With the new MkW ANVIL, we’re offering our customers a rifle that’s been engineered to maximize the performance of this exciting caliber,” he said.
A Picatinny rail sits atop the rifle ready to accept sights and optics. CMMG’s RKM15 KeyMod hand guard also gives shooters options by accepting a variety of accessories for mounting in three slot positions. If accessories are not KeyMod complaint, CMMG alternatively offers five slot accessory rails for mounting accessory needs.
The .458 SOCOM round is a bit of a novelty as most AR fans prefer the standard 5.56mm round. The concept for a powerful round that would fit within the confines of the M4 and its magazines and could fire at subsonic levels with a suppressor was born out of disastrous Task Force Ranger debacle in Mogadishu, Somali — later transformed into the 2001 film Black Hawk Down.
While pinned down and with little hope of survival, the Rangers commented on the obvious lack of ineffectiveness the 5.56 round had on the Somalian rebels. The discussion resulted into the idea for an entirely new cartridge with increased “stopping power.”
In 2000, Teppo Jutsu introduced the .458 SOCOM which offered velocities of 1,600 to 3,000 feet per second out of 140 to 400 grain bullets.
Several companies including Black Butterfly Ammunition, Corbon, Lehigh Defense, Polycase, Southern Ballistic Research, Underwood Ammunition and Ventura Munitions offer the .458 SOCOM to consumers.