300 Blackout Bolt Action SBR with Compact Suppressed Performance
The CM7S 300 Blackout Bolt Action SBR is a compact, suppressor-ready firearm manufactured around the practical strengths of the .300 AAC Blackout cartridge. Its 10-inch, 1:5 twist Mos-Tek barrel provides the barrel length and rotational stability CM prefers for heavy subsonic projectiles, while the telescoping rear assembly keeps the complete firearm short and maneuverable.
This FDE Metallic configuration combines the PVD-coated CM7S three-lug action, a 416R stainless Mos-Tek barrel, TriggerTech Rem 700 Primary trigger and billet-aluminum CM7 chassis. It is intended for customers who want bolt-action simplicity, a short overall length and the ability to evaluate different subsonic and supersonic loads without tuning a semi-automatic gas system.
The SBR configuration uses a telescoping buttpad with an adjustable cheek riser. A pistol configuration with a telescoping Tailhook brace is also available. The selected rear assembly determines the firearm’s legal classification.
Explore the complete Sector 300 ecosystem for related CM7S and CM15 firearms, magazines and technical information.
Why Choose a 300 Blackout Bolt Action SBR?
A 300 Blackout Bolt Action SBR combines the compact dimensions of a short-barreled firearm with the ammunition flexibility of a manually operated action. Unlike a semi-automatic platform, the CM7S does not rely on ammunition-generated gas pressure to cycle. Moving between different subsonic loads or between subsonic and supersonic ammunition does not require gas-block or buffer adjustments.
The action remains closed until the shooter manually cycles the bolt. During suppressed shooting, that eliminates the action movement and operating-gas discharge associated with a semi-automatic firearm. The result is a straightforward suppressor host that does not depend on additional backpressure for reliable operation.
Chattahoochee Munitions considers 10–10.5 inches the optimal general-purpose barrel range for its .300 Blackout firearms. A 10-inch barrel maintains compact handling while providing useful powder utilization for CM’s intended subsonic and suppressed applications.
CM7S Three-Lug Bolt Action
The CM7S is a steel action with a Remington 700-style short-action footprint. Its three-lug bolt produces a 60-degree throw, providing fast operation and additional clearance beneath an installed optic. Wire EDM raceways support consistent tolerances and smooth bolt movement.
- Remington 700-style footprint
- Three-lug action
- 60-degree bolt throw
- M16-style extractor
- One-piece bolt with a 0.718-inch bolt-body diameter
- Wire EDM raceways
- Integrated 0.300-inch recoil lug
- Pinned 20 MOA Picatinny optics rail
- Large ejection port
- Lightened action body
- Approximately 25-ounce action weight
- 0.062-inch firing pin compatible with small-rifle-primer brass
- Tool-less fire-control removal
- Accepts Remington 700-style triggers
- 1-1/16-inch-16 barrel thread
- Side bolt-stop release
- Oversized bolt knob
- Spiral-fluted bolt
- Full PVD coating for corrosion resistance and smooth operation
10-Inch Mos-Tek Barrel with 1:5 Twist
The barrel is a defining component of this 300 Blackout Bolt Action SBR. Chattahoochee Munitions uses a 10-inch Mos-Tek bolt-action barrel manufactured from 416R stainless steel. The barrel is installed using the Remage system and protected by E100 Blackout Cerakote.
Its 1:5 twist provides increased rotational stability for long, heavy subsonic projectiles. The fast twist is particularly useful in a compact .300 Blackout barrel, but projectile stability should always be confirmed with the selected ammunition before attaching a suppressor.
- Caliber: .300 AAC Blackout / 300 BLK
- Barrel length: 10 inches
- Barrel manufacturer: Mos-Tek
- Material: 416R stainless steel
- Rifling: 5R
- Twist rate: 1:5
- Crown: Shouldered crown
- Muzzle thread: 5/8×24
- Barrel installation: Remage barrel nut
- Finish: E100 Blackout Cerakote
Suppressor-Ready Bolt-Action Configuration
The barrel’s 5/8×24 muzzle thread accepts many compatible .30-caliber suppressor mounts, direct-thread suppressors and muzzle devices. Suppressors vary in bore diameter, mounting system, overall length, weight and pressure characteristics. Compatibility should be verified with the suppressor and mount manufacturers before installation.
A conventional enclosed suppressor is generally the more suitable choice when sound reduction with subsonic .300 Blackout is the priority. Flow-through suppressors can perform well with supersonic ammunition, but their reduced backpressure is primarily beneficial to semi-automatic systems. The manually operated CM7S does not require suppressor backpressure to cycle.
This 300 Blackout Bolt Action SBR is suppressor-ready but is not an SD configuration. The suppressor attaches forward of the muzzle rather than extending inside or beneath the chassis forend. A suppressor is not included with the firearm.
TriggerTech Rem 700 Primary Trigger
The firearm includes a TriggerTech Rem 700 Primary trigger with the customer’s choice of a flat or curved trigger lever. TriggerTech’s Frictionless Release Technology provides a crisp break with minimal overtravel.
Pull weight is externally adjustable from 1.5 to 4.0 pounds in one-ounce increments. Hardened 440C stainless-steel internal components provide corrosion resistance and extended service life. Product photographs may depict an earlier flat trigger with a removable shoe; current flat triggers no longer use that shoe.
FDE Metallic CM7 Chassis
The CM7 chassis is machined from a single block of billet aluminum and finished in FDE Metallic Cerakote. Its compact dimensions complement the purpose of the 300 Blackout Bolt Action SBR, while its adjustable rear interface supports different shooters, clothing and firing positions.
- FDE Metallic Cerakote finish
- Single-piece billet-aluminum construction
- Flared magazine well for AICS-pattern magazines
- Ambidextrous magazine release
- Large trigger guard for gloved operation
- Accepts AR-15 pistol grips without an integrated dovetail
- Modular rear-interface system
- M-LOK-compatible forend
- Dual integrated QD sling sockets
- Full-length bottom ARCA rail
The firearm includes a CM Precision Vertical Crossover Grip developed in collaboration with MK Machining and finished in AI Dark Earth Cerakote. It also includes a CM-vetted 10-round AICS-pattern magazine in AI Dark Earth Cerakote.
Additional magazines are available through the CM 300 Blackout bolt-action magazine page.
SBR and Pistol Configuration Options
The 300 Blackout Bolt Action SBR configuration uses a telescoping buttpad and adjustable cheek riser. This provides a compact stored length while allowing the rear assembly to be extended for the shooter’s preferred length of pull.
- SBR: Telescoping buttpad with adjustable cheek riser
- Pistol: Telescoping Tailhook brace with adjustable cheek riser
- Chassis and rear finish: FDE Metallic Cerakote
- Grip and magazine finish: AI Dark Earth Cerakote
The SBR must be shipped to an appropriately licensed SOT/FFL and transferred following the required National Firearms Act approval process. Customers are responsible for compliance with all federal, state and local requirements. State laws may separately regulate SBR possession, suppressor possession, hunting use and permissible firearm configurations.
Subsonic and Supersonic Ammunition
The manually operated action allows this firearm to use compatible subsonic and supersonic .300 Blackout ammunition without gas-system tuning. That does not mean different loads will produce identical results.
- Subsonic ammunition: Uses heavier projectiles and prioritizes reduced sound when paired with an appropriate suppressor.
- Supersonic ammunition: Provides higher velocity, a flatter trajectory and a different terminal-performance envelope.
Even two subsonic loads can produce different velocity, accuracy and point of impact. Each selected load should be tested through the firearm and suppressor combination that will be used. Hunters must also select projectiles that provide suitable terminal performance at the expected impact velocity.
Read the Chattahoochee Munitions 300 Blackout subsonic guide for additional information about barrel length, twist rate, suppressors and ammunition selection.
Compact Dimensions and Field Utility
A useful 300 Blackout Bolt Action SBR must remain compact as a complete system, including its optic, muzzle device and suppressor. This CM7S weighs 6 pounds 2 ounces and measures 22.5–30.0 inches before a suppressor is attached. Starting with a 10-inch barrel helps control the system’s final length when the suppressor extends forward of the muzzle.
The full-length bottom ARCA rail provides an interface for compatible tripods and shooting supports. Dual QD sockets offer sling-mounting options, while the adjustable cheek riser helps establish a consistent position behind the optic.
Complete Firearm Specifications
- Manufacturer: Chattahoochee Munitions
- Model: CM7S
- Caliber: .300 AAC Blackout / 300 BLK
- Action: Three-lug bolt action
- Barrel length: 10 inches
- Twist rate: 1:5
- Muzzle thread: 5/8×24
- Trigger: TriggerTech Rem 700 Primary, flat or curved
- Chassis: CM7 billet-aluminum chassis
- Magazine pattern: AICS
- Included magazine: One CM-vetted 10-round AICS-pattern magazine
- Finish: FDE Metallic and AI Dark Earth Cerakote
- Weight: 6 pounds 2 ounces
- Overall length: 22.5–30.0 inches
- Length of pull: 6.0–13.5 inches
- Warranty: Limited lifetime warranty for the original purchaser, subject to applicable terms
Note: Weight and dimensions displayed in the separate WooCommerce information tab are for shipping purposes. The specifications above describe the firearm.
Frequently Asked Questions
What makes this firearm an SBR?
The combination of a shoulder stock or buttpad and a barrel shorter than 16 inches places the selected SBR configuration within the applicable short-barreled-rifle classification. It must be transferred through the required NFA process.
Can this product be ordered as a pistol?
Yes. The pistol option replaces the telescoping buttpad with a telescoping Tailhook brace. The selected option determines the firearm’s final configuration and transfer requirements.
Does the firearm include a suppressor?
No. The barrel is threaded 5/8×24 for compatible suppressor mounts and muzzle devices, but the suppressor is selected separately.
Why use a bolt action for suppressed .300 Blackout?
The action remains closed during firing and does not require gas pressure to cycle. This avoids semi-automatic gas-system tuning and allows different compatible loads to be evaluated without adjusting an operating system.
Why does CM use a 1:5 twist barrel?
The 1:5 twist provides increased rotational stability for long, heavy subsonic projectiles. Ammunition should still be tested for accuracy and stability before a suppressor is attached.
Is this an SD firearm?
No. It is suppressor-ready, but the suppressor mounts forward of the muzzle. CM uses the SD designation when the suppressor extends inside or beneath the handguard or forend.
Is the barreled action available separately?
Yes. Customers who already have compatible supporting components can explore the CM7S 300 Blackout bolt action page for the 10-inch barreled-action configuration.
A Purpose-Manufactured Compact Bolt Action
The CM7S 300 Blackout Bolt Action SBR combines a 10-inch, 1:5 twist Mos-Tek barrel, PVD-coated three-lug action, TriggerTech Primary trigger and FDE Metallic CM7 chassis. It is a complete Chattahoochee Munitions firearm manufactured for compact handling, suppressor compatibility and dependable operation with appropriately selected .300 Blackout ammunition.
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