When it comes to rifles, I tend to stick to NATO-standard calibers: 5.56mm and .308 Win. Not because I think these calibers are especially potent or effective, but simply because of how affordable and plentiful they are. The same can be said of the rifles I like to purchase, so that replacement parts are inexpensive and easily found in an emergency. So you can imagine my surprise when I broke both of these rules and fell head over heels for the newest rifles from CMMG, the Anvil.

The Anvil is a direct impingement, semi-automatic rifle chambered in .458 SOCOM – a round powerful enough to take the largest boar or bear without any issues. It feeds from STANAG or standard AR-15 magazines, and includes one Lancer L5 AWM with the rifle.

Externally, the Anvil simply looks like an over-grown AR15. Which ostensibly, it is. Unlike most big bore modern sporting rifles on the market today, the Anvil isn’t built on AR15. The rifle instead is built on a much stronger foundation: an AR10 – the normally .308-caliber big brother to America’s favorite black rifle.


The MkW ANVIL is built with a carbine-length gas system and utilizes an SLR Rifleworks Sentry 7 adjustable gas block. This allows users to easily adjust the gas metering in click-adjustments to work with varying loads of .458 SOCOM ammunition.

This alone is enough to make the rifle stand out from the countless numbers of odd-caliber ARs on the market today; but CMMG doesn’t just phone it in, supplying a totally bare-bones carbine in an exotic caliber. The Anvil ships with impressive features like a full-length, free-floated KeyMod rail featuring a Picatinny rail running its length. It also ships with a nice, two-stand competition trigger, Magpul MOE pistol grip and collapsible stock.

Which is another strong suite of the rifle, it uses mostly AR15 components – from stocks and pistol grips to magazines, this is a rifle with cost of ownership in mind. Even if the ammunition doesn’t extend the same curtesy.

Which is the 600-pound gorilla in the room, feeding this beastly automatic.

The .458 SOCOM round itself is designed to replicate the ballistics of the venerable .45-70 Gov cartridge.

The .458 SOCOM round itself is designed to replicate the ballistics of the venerable .45-70 Gov cartridge.

.458 SOCOM isn’t a common caliber by any stretch, but isn’t quite in the realm of unicorn-tier rounds either. In my research, I found a surprisingly large number of ammo manufacturers churning out this cannon balls that pass for cartridges. Even more surprising, is the range of projectile weights. available.

Ammo makers like relative industry newcomer, Black Butterfly Ammunition sells Nosler ballistic tip rounds weighing in at a whopping 300 grains. While Polycore offers some of their lead-free polymer rounds at a featherweight 120 grains screaming at more than 2500fps! Suppressor-lovers can rejoice as well, a 980 fps subsonic 500 grain soft point round is also available from Strike Force Ammunition.

Is this round the new .500 S&W, simply a treat for shooters who love painful shoulders?

I don’t think so, the .458 SOCOM round itself is designed to replicate the ballistics of the venerable .45-70 Gov cartridge. This round has proven itself a real man-stopper on nearly every continent, and when loaded properly can be used to take cape buffalo.

Domestic hunters too can appreciate the round’s raw power, it allows them to take deer through thick brush, while also making a great danger game round. I can see this rifle becoming very popular with wild boar hunters who like to stalk hunt, as it provides great stopping power, and fast reloads.

More than just powerful, the Anvil performed very well in accuracy tests when shot from a rest. Firing at a standard NRA scaled rifle target, the CMMG Anvil produced groups hovering just under two inches. Given the round’s steep ballistic arch, this level of precision is more than enough for hunters or tactical shooters.

Overall I had a great time blast away at fruit, steel and any other reactive targets I could get my mitts on. I just wish the rifle had arrived closer to deer season, so I could try out its impressive ballistics in the field. Though, I’m certain given how hard hitting the heavy rounds are, it would make short work of any target on two or four legs in North America.

CMMG MkW Anvil Specs:

Caliber: .458 SOCOM
Barrel: 16.1″, 1:14 Twist, Medium Taper, 416SS, SBN
Muzzle: CMMG SV muzzle brake, Threaded 5/8-32
Hand Guard: CMMG RKM15 KeyMod
Upper Receiver: Billet 7075-T6 AL Mid-Size
Lower Receiver: Billet 7075-T6 AL Mid-Size
Trigger: Single Stage Mil-Spec Style Trigger
Furniture: Mil Spec Grip and Butt stock
Weight: 7.5 lbs (Unloaded)
Length: 33.5″ (Stock Collapsed)
MSRP: $1,849.95