CMMG MkW-15 ANVIL XBE .458 SOCOM Semi-Auto AR with 16.1 in Nitride 416SS Barrel, Billet Receivers, Adjustable Gas Block, and KeyMod Handguard
The CMMG MkW-15 ANVIL XBE is a purpose-built, big-bore AR chambered in .458 SOCOM. It uses mid-size 7075-T6 billet receivers with an enlarged bolt and carrier group to handle the cartridge, and pairs a 16.1 in medium-taper 416 stainless barrel with salt-bath nitride treatment, an adjustable gas block, and a free-float KeyMod handguard. This XBE is the standard trim (not XBE2), featuring a mil-spec single-stage trigger and a compliant, tool-activated magazine release.
Condition
Overall Condition: Very good condition, showing only light, superficial signs of prior handling or use.
Bore Overall Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: The rifle is in solid functional shape. Exterior surfaces show scattered scratches and small blemishes from prior handling.
What’s Included
- CMMG MkW-15 ANVIL XBE .458 SOCOM semi-automatic rifle
- One Lancer L5AWM 4-round magazine marked .458 SOCOM
Built as a dedicated big-bore variant, the MkW-15 ANVIL XBE uses mid-size 7075-T6 billet receivers and an enlarged bolt and BCG tailored for .458 SOCOM. The upper is a flat-top design with a full-length 1913 Picatinny rail, a brass deflector, and an ejection-port cover, and it omits the forward assist. Receiver markings include the CMMG logo, MkW-15 model designation, and CMMG INC FAYETTE MO USA. The selector legend reads SAFE and SENT.
The 16.1 in 416 stainless steel barrel features a medium-taper profile and salt-bath nitride treatment. It is threaded 5/8x32 and fitted with a multi-port muzzle brake/compensator. A carbine-length gas system with an adjustable gas block is accessible through the handguard for tuning.
The free-float aluminum KeyMod handguard is approximately 15 in long with a continuous top rail, offering solid accessory mounting while keeping the barrel free-floated. There are no sights installed from the factory.
Controls and furniture are straightforward and duty-oriented: a mil-spec single-stage trigger, manual safety selector, adjustable 6-position polymer stock, and a Magpul MOE pistol grip. The magazine release has been swapped for a compliant, tool-activated design. The rifle accepts AR-15 pattern magazines adapted for .458 SOCOM and ships with one Lancer L5AWM 4-round magazine. This is the XBE standard configuration (not XBE2), and it uses a mil-spec trigger rather than a Geissele unit.