CM7S 8.6 Blackout 12″ Barreled Action

8.6 Blackout Barreled Action | CM7S 12″ Bolt Action

The CM7S 8.6 Blackout Barreled Action combines the Chattahoochee Munitions CM7S action with a compact 12-inch barrel to provide the foundation for a custom 8.6 Blackout bolt-action build. It allows the customer to start with the action and barrel assembly, then select the chassis, trigger, grip, magazine and rear configuration around the intended use of the finished firearm.

The CM7S uses a Remington 700 short-action footprint with a three-lug bolt, 60-degree throw, integrated recoil lug and pinned 20 MOA Picatinny rail. The 12-inch barrel is available with either a 1:3 or 1:5 twist, allowing the build to be configured around the projectile and ammunition it is intended to use.

Customers who want to build around CM components can pair the barreled action with the CM7S Bolt Action Chassis, TriggerTech R700 Primary, Vertical Precision Crossover Grip and CM-vetted 8.6 Blackout Magazine.

CM7S Action

The action at the center of the 8.6 Blackout Barreled Action is the same CM7S architecture used throughout our complete 8.6 Blackout bolt-action firearm family.

• Remington 700 short-action footprint
• Three-lug bolt design
• 60-degree bolt throw
• M16-style extractor
• One-piece .718″ bolt body
• Wire EDM raceways
• Pinned 20 MOA Picatinny rail
• Large ejection port
• Lightweight action-body cutout
• .062″ firing pin
• Integrated .300″ recoil lug
• Tool-less fire-control removal
• Accepts compatible Remington 700-style triggers
• 1-1/16″-16 barrel thread
• Side bolt-stop release
• Oversized bolt knob
• Spiral-fluted bolt
• Full PVD coating
• Action weight: 25 oz

The Remington 700 footprint provides access to a broad component ecosystem while also allowing the CM7S action to be paired directly with CM’s chassis and supporting components.

12″ Mos-Tek 8.6 Blackout Barrel

The 12-inch barrel supplied with this 8.6 Blackout Barreled Action is a Mos-Tek premium bolt-action barrel manufactured from 416R stainless steel with 5R rifling and finished in E100 Blackout Cerakote.

• 12″ barrel length
• 416R stainless steel
• 5R rifling
• Choice of 1:3 or 1:5 twist
• Shouldered crown
• 5/8×24 muzzle threads
• Remage barrel interface
• E100 Blackout Cerakote

CM offers both twist rates because projectile construction, length, weight, ammunition, velocity and barrel length all influence stabilization. Neither 1:3 nor 1:5 should be treated as universally correct for every 8.6 Blackout load.

For a deeper discussion of CM testing with barrel length, twist rate, projectile weight and suppression, read our 8.6 Blackout Subsonic Guide.

Why a 12″ 8.6 Blackout Barreled Action?

The 12-inch 8.6 Blackout Barreled Action occupies a useful middle ground in the CM7S lineup. It is substantially shorter than the 16-inch configuration without making the same minimum-length tradeoff as the 8-inch version.

That distinction becomes particularly relevant when the finished firearm will be suppressed. A 12-inch host can reduce the overall length of the complete suppressed system while retaining additional barrel length compared with an 8-inch build.

CM has been working with 8.6 Blackout since the cartridge’s early introduction, and in the subsonic loads we have evaluated, powder utilization has been effectively complete at approximately 12 to 12.5 inches. That makes the 12-inch configuration an especially useful option for customers building around suppressed and subsonic use.

This is an observation from CM’s testing with the loads we have evaluated rather than a universal rule for every 8.6 Blackout ammunition combination. Projectile, powder, load, barrel and suppressor configuration all matter.

Choosing Between 1:3 and 1:5 Twist

The 8.6 Blackout Barreled Action is available with either a 1:3 or 1:5 twist because CM does not treat one twist rate as universally superior.

In CM testing with barrels around 12 to 12.5 inches, 1:5 has generally stabilized projectiles around 300 grains or less well, while 1:3 has generally been better suited to heavy subsonic projectiles around 323 grains and above.

Those observations are a practical configuration guide based on the ammunition and firearms we have tested. Projectile construction, projectile length, weight and velocity can change the appropriate choice, so the intended ammunition should be considered when selecting the barrel twist.

Complete Your CM7S 8.6 Blackout Build

Starting with a CM7S 8.6 Blackout Barreled Action allows the customer to choose the remaining components instead of purchasing a complete firearm and replacing parts afterward. CM offers the major supporting components needed to build out the CM7S platform.

CM7S Bolt Action Chassis

The CM7S Bolt Action Chassis provides a purpose-built chassis option for the CM7S action. Its billet-aluminum construction incorporates an AICS-pattern magazine well, ambidextrous magazine release, M-LOK compatibility, integrated QD sling sockets and a full-length bottom ARCA rail.

TriggerTech R700 Primary

The CM7S accepts compatible Remington 700-style triggers. CM offers the TriggerTech R700 Primary for customers who want to use the same trigger family offered in our complete CM7S firearms.

Vertical Precision Crossover Grip

The CM Vertical Precision Crossover Grip, developed in collaboration with MK Machining, can be paired with the CM7S chassis to complete the grip interface.

CM-Vetted 8.6 Blackout Magazine

Magazine selection is part of the complete firearm system. Instead of assuming that every generic short-action AICS magazine will feed 8.6 Blackout identically, CM offers a vetted 8.6 Blackout Magazine for the CM7S platform.

Build Around the Complete System

The 8.6 Blackout Barreled Action is intended to serve as the foundation rather than dictate every component of the finished firearm. The customer can choose the chassis, trigger, grip, rear configuration, optic and suppressor around the intended application.

Using CM components creates a straightforward build path:

• CM7S 12″ barreled action
• CM7S bolt-action chassis
• TriggerTech R700 Primary trigger
• CM Vertical Precision Crossover Grip
• CM-vetted 8.6 Blackout magazine

Customers who prefer a complete firearm rather than assembling the system from components can compare the full CM7S lineup in Area 8.6.

Suppressed 8.6 Blackout Configuration

The 12-inch barrel terminates in 5/8×24 muzzle threads for compatible muzzle devices and suppressor mounting systems. Compatibility should be verified for the specific suppressor, ammunition and firearm configuration.

A bolt-action host also removes the requirement to tune ammunition around the gas and buffer systems necessary to cycle a semi-automatic firearm. That makes the platform particularly flexible when working with specialized subsonic ammunition.

For a suppressed build, the 12-inch barrel provides a useful balance between barrel length and the overall length added by a suppressor. Customers who prioritize the shortest possible host can also consider the 8-inch barreled action, while the 16-inch version provides a conventional rifle-length alternative.

CM7S 12″ 8.6 Blackout Barreled Action Specifications

Platform	CM7S Bolt Action
Caliber	8.6 Blackout
Action Footprint	Remington 700 Short Action
Bolt	Three Lug, 60-Degree Throw
Action Finish	PVD
Optic Rail	Pinned 20 MOA Picatinny
Barrel Length	12″
Barrel Manufacturer	Mos-Tek
Barrel Material	416R Stainless Steel
Rifling	5R
Twist Rate	1:3 or 1:5
Muzzle Threads	5/8×24
Barrel Finish	E100 Blackout Cerakote
Barrel Interface	Remage
Trigger Compatibility	Remington 700 Pattern
Barreled Action Weight	57.4 oz / 3.59 lb

8.6 Blackout Barreled Action FAQ

What is included with the 12″ 8.6 Blackout Barreled Action?

The product combines the CM7S Remington 700-footprint action with a 12-inch 8.6 Blackout barrel. The chassis, trigger, grip and magazine can be selected separately to complete the firearm.

Can I complete the build with CM components?

Yes. CM offers the CM7S Chassis, TriggerTech R700 Primary, Vertical Precision Crossover Grip and vetted 8.6 Blackout Magazine.

Why choose the 12″ barrel?

The 12-inch configuration provides a compact host while retaining more barrel length than the 8-inch version. In the subsonic loads CM has evaluated, powder utilization has been effectively complete at approximately 12 to 12.5 inches, making this a particularly useful configuration for suppressed and subsonic builds.

Should I choose a 1:3 or 1:5 twist?

The appropriate twist depends on projectile construction, length, weight, velocity and intended ammunition. In CM testing around this barrel length, 1:5 has generally performed well with projectiles around 300 grains or less, while 1:3 has generally been better suited to heavy subsonic projectiles around 323 grains and above.

Is the barrel suppressor compatible?

The barrel uses 5/8×24 muzzle threads for compatible muzzle devices and suppressor mounting systems. Compatibility should be verified with the specific suppressor and ammunition being used.

What magazine should I use?

The CM7S uses an AICS-pattern magazine architecture. CM offers a vetted 8.6 Blackout Magazine specifically for the bolt-action platform.

Where can I compare other CM 8.6 Blackout configurations?

Visit Area 8.6 to compare complete CM7S firearms, CM10 AR10 platforms, barreled actions and supporting 8.6 Blackout components.