CM7S 308 Subsonic Bolt Action
The CM7S 308 Subsonic Bolt Action combines a 12.5-inch Mos-Tek barrel with a fast 1:5 twist designed to stabilize long, heavy subsonic projectiles. Its manually operated three-lug action, Black Tungsten chassis and selectable pistol or SBR configuration create a compact 308 Winchester system for suppressed shooting.
Select the pistol configuration with a telescoping Tailhook brace or the registered short-barreled rifle configuration with a telescoping buttpad. Both options include an adjustable cheek riser and retain the same CM7S action, barrel, chassis and short-action AICS magazine system.
At 6 pounds 6 ounces, the firearm remains portable while providing a full bottom ARCA rail, M-LOK mounting surfaces and broad brace or stock adjustment. Its verified overall length ranges from 25.375 to 32.5 inches, with a 6-inch to 13.5-inch length of pull.
Explore CM’s complete family of 308 Winchester firearms, ammunition, magazines and technical guides in District 308.
Pistol and SBR Configurations
- Pistol configuration: Telescoping Tailhook brace with an adjustable cheek riser
- SBR configuration: Telescoping buttpad with an adjustable cheek riser
The SBR configuration is an NFA firearm and must complete the applicable federal transfer process. The pistol configuration does not include a shoulder stock. Review CM’s NFA firearms information for transfer guidance and available Form 4 services.
Mos-Tek 12.5-Inch Subsonic Barrel
The barrel is produced through CM’s collaboration with Mos-Tek. It is machined from 416R stainless steel, uses 5R rifling and receives E100 Blackout Cerakote for external protection.
The defining specification is the 1:5 twist. CM’s 300-grain Maker REX projectile measures 2.06 inches long and travels at approximately 1,005 feet per second from this barrel configuration. Its combination of exceptional length and subsonic velocity requires substantially more rotational speed than a conventional 1:8 or 1:10 twist barrel can provide.
The fast twist gives the 308 Subsonic Bolt Action the stability required for CM’s specialized 300-grain ammunition. The shouldered crown protects the muzzle, while 5/8×24 threads accept compatible direct-thread suppressors and suppressor mounts.
Barrel Specifications
- Manufacturer collaboration: CM and Mos-Tek
- Chambering: 308 Winchester
- Barrel length: 12.5 inches
- Material: 416R stainless steel
- Rifling: 5R
- Twist rate: 1:5
- Crown: Shouldered crown
- Muzzle threads: 5/8×24
- Barrel attachment: Remage barrel nut
- Finish: E100 Blackout Cerakote
CM7S Three-Lug Bolt Action
The CM7S action uses the established Remington 700 footprint with a three-lug bolt and 60-degree throw. The shorter bolt rotation limits handle travel and provides additional clearance around the optic during operation.
A one-piece .718-inch bolt body, M16-style extractor and integrated .300-inch recoil lug provide the mechanical foundation of the 308 Subsonic Bolt Action. Wire EDM-cut raceways establish uniform tolerances, while the oversized bolt knob and spiral-fluted bolt support smooth manual operation.
The action and bolt receive a full PVD coating for corrosion resistance and reduced operating friction. A pinned 20-MOA Picatinny rail provides a stable optic interface, while the large ejection port offers clear access to the chamber and action.
CM7S Action Features
- Remington 700 footprint
- Three-lug action with a 60-degree bolt throw
- M16-style extractor
- One-piece bolt with a .718-inch bolt-body diameter
- Spiral-fluted bolt
- Wire EDM-cut raceways
- Pinned 20-MOA Picatinny optic rail
- Large ejection port
- Lightened action body
- Approximately 25-ounce action weight
- .062-inch firing pin compatible with small-rifle-primer brass
- Integrated .300-inch recoil lug
- Tool-less fire-control removal
- Remington 700 trigger compatibility
- 1-1/16-inch-16 barrel thread pitch
- Side bolt-stop release
- Oversized bolt knob
- Full PVD coating
TriggerTech Remington 700 Primary Trigger
The CM7S uses a TriggerTech Remington 700 Primary trigger, available with a flat or curved trigger bow. TriggerTech’s Frictionless Release Technology provides a zero-creep break with short overtravel and consistent operation.
Pull weight is externally adjustable from 1.5 to 4 pounds in one-ounce increments. Hardened 440C stainless steel internal components provide corrosion resistance and extended service life. Current flat triggers do not use the removable trigger shoes shown in some earlier CM photographs.
Black Tungsten CM7S Chassis
The chassis is machined from a single block of billet aluminum and finished in Black Tungsten Cerakote. Black and Black Tungsten brace or stock components complete the dark presentation of this compact subsonic configuration.
The flared magazine well accepts compatible short-action AICS-pattern magazines. An ambidextrous magazine release permits operation from either side, while the enlarged trigger guard provides additional clearance when gloves are worn.
A full bottom ARCA rail supports compatible tripods, bipods and supported-position equipment. M-LOK mounting surfaces provide additional accessory space, and dual integrated QD sockets supply sling attachment points on both sides of the chassis.
Chassis and Brace Features
- Machined from a single block of billet aluminum
- Black Tungsten Cerakote chassis
- Black and Black Tungsten brace or stock components
- Flared short-action AICS-pattern magazine well
- Ambidextrous magazine release
- Large trigger guard for gloved operation
- Accepts AR15 pistol grips without an integrated dovetail
- Modular single-bolt stock-adapter system
- Telescoping pistol-brace or SBR-buttpad configuration
- Adjustable cheek riser
- M-LOK compatibility
- Dual integrated QD sling sockets
- Full bottom ARCA rail
CM Vertical Crossover Grip
The firearm uses the CM Precision Vertical Crossover Grip developed in collaboration with MK Machining. Its geometry supports a more vertical firing-hand position while retaining practical handling across supported and unsupported positions.
300-Grain 308 Subsonic Ammunition
CM’s 308 subsonic ammunition uses a 300-grain Maker REX projectile loaded in new Starline 308 Winchester brass. From CM’s 12.5-inch 1:5 twist barrel, the load averages approximately 1,005 feet per second.
The manually operated action does not depend on ammunition pressure for cycling. The 308 Subsonic Bolt Action can therefore fire compatible subsonic ammunition with or without a suppressor.
CM’s 300-grain ammunition should not be fired through a conventional 1:8 or 1:10 twist barrel. A slower twist can allow the long projectile to yaw or tumble, degrading accuracy and creating the possibility of a suppressor baffle or end-cap strike.
Read the 308 Winchester Subsonic Guide for the complete explanation of projectile length, velocity, stability and twist-rate requirements.
Suppressing a 308 Subsonic Bolt Action
A bolt action does not use propellant gas to cycle, allowing the firearm to operate with or without a suppressor. CM generally recommends an enclosed suppressor for this configuration because backpressure does not have to be balanced against semi-automatic bolt speed or receiver gas.
Subsonic ammunition eliminates the supersonic flight crack, while the suppressor reduces the muzzle report. The firearm is not silent; remaining sound includes the action, escaping gas and projectile impact.
The suppressor must be rated for 308 Winchester, the 12.5-inch barrel and the intended firing schedule. Confirm mounting compatibility, suppressor-to-bore alignment and manufacturer restrictions before firing.
The 308 Suppressor Guide explains CM’s recommendations for subsonic bolt actions, supersonic semi-automatics and the specialized CM10 SUBSONIC.
AICS Magazine Compatibility
The CM7S accepts compatible polymer or metal short-action AICS-pattern magazines. It does not use the LR/SR-pattern magazines found in conventional CM10 semi-automatic rifles.
The available 308 bolt-action magazine is a 10-round Magpul PMAG 7.62 AC selected for the CM7S platform.
Custom Cerakote Options
Each firearm is manufactured to order. A single-color Cerakote finish can be substituted at no additional charge. Camouflage patterns and multicolor finishes add $300.
After placing the order, contact CM with the requested finish. CM will confirm the change and provide a separate invoice when an additional finish charge applies.
308 Subsonic Bolt Action Dimensions
- Verified weight: 6 pounds 6 ounces
- Verified overall length: 25.375 to 32.5 inches
- Verified length of pull: 6 to 13.5 inches
- Magazine pattern: Short-action AICS
These are verified firearm measurements. Any different weight or dimensions displayed elsewhere in the product interface are shipping values rather than firearm specifications.
CM Limited Lifetime Warranty
The CM7S 308 Subsonic Bolt Action pistol or SBR is covered by the Chattahoochee Munitions limited lifetime warranty for the original purchaser. Coverage applies to the functional operation of the firearm in its original CM configuration when appropriate ammunition is used.
Review the complete Chattahoochee Munitions warranty for coverage terms and exclusions.
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