First Look: CMC 6 mm ARC Suppressor Optimized Enhanced Bolt Carrier Group

posted on June 18, 2020

CMC Triggers is releasing its new Suppressor Optimized Enhanced Bolt Carrier Group, designed for the Hornady 6 mm ARC round, and designed for shooters who demand superior performance weapon components in the heart of their firearm.

The carrier assembly and flared rear of the enhanced bolt carrier is designed to reduce carrier tilt/cant during recoil and increase reliability by relocating key surfaces. The CMC enhanced carrier has fewer points of contact, which results in less friction area. Its increase in mass also ensures proper gas pressures and increases dwell time, which improves extraction when shooting with a short barrel or a suppressor.

The bolt assembly is manufactured to a true Mil-Spec dimension, and the external surfaces on the bolt are ground after heat treatment for a precision fit. The bolt is machined to the 6 mm ARC (Advanced Rifle Cartridge) Hornady factory-round specification and is held to the highest possible tolerances. The “trumpet” area behind the gas rings, where carbon normally collects, is precision CNC Ground after heat treatment to ensure as smooth of an area as possible, easing clean up and longevity.

Carrier Assembly Features:
Case-hardened 8620 steel (complete care is taken during the heat treat process, so as to not harm the metal)
Three forward ports, enlarged to allow overpressure to escape
Optimized for suppressor use
Black Nitride finish
4130 Steel, attached with Grade 8 hardware, torqued and properly staked into a milled “valley” around a fully encased ejection port area, for added strength and rigidity
Hardened 4340 cam pin
Fully chamfered cam pin channel
Mil-Spec firing pin made of AISI 8740 steel, centerless ground and Hard Chrome coated

Bolt Assembly Features:
9310 Case Hardened Steel
All bolt components Shot Peened and Black Nitride coated
4340 Steel, Manganese Phosphate coated
Magnetic Particle Inspected (MPI) and High Pressure Tested (HPT)
Black Nitride low friction coating
Mil-Spec Billet Extractor Spring and CRANE O-Ring Upgrade
6 mm ARC Advanced Rifle Cartridge from Hornady Bolt. 6ARC Specific.
Black Nitride Finish

The Suppressor Optimized Enhanced Bolt Carrier Group carries CMC's Satisfaction Guarantee and Lifetime Warranty and has an MSRP of $199. More information on this new bolt carrier group and other CMC Triggers products is available at


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