CM7S 338 ARC Bolt Action SBR – 12.5″ WOOX Walnut
The CM7S 338 ARC Bolt Action SBR combines a compact 12.5-inch 338 ARC barrel with the walnut and aluminum WOOX hunting platform. Built around the Chattahoochee Munitions CM7S action, a MÔS-Tek 1:5 twist barrel, TriggerTech Primary trigger, WOOX Exactus stock, and Furiosa forend, this configuration blends modern bolt-action performance with traditional walnut hunting-rifle ergonomics.
At approximately 7 pounds 12 ounces and 31.750 to 32.50 inches overall, the 12.5-inch WOOX configuration is substantially more compact than a conventional full-length hunting rifle while retaining an adjustable shoulder stock and full-size bolt-action interface.
Chattahoochee Munitions has extensive experience manufacturing and testing heavy .338-caliber systems. Based on our testing of the 338 ARC loads we have evaluated, powder utilization occurs largely around the 12-inch barrel-length range. That makes the 12.5-inch barrel a particularly useful pairing with this compact 338 ARC Bolt Action SBR.
CM7S Bolt Action – Full PVD Coating
The foundation of the 338 ARC Bolt Action SBR is the Chattahoochee Munitions CM7S action. It uses the familiar Remington 700 footprint while incorporating features selected specifically for our precision and hunting firearm systems.
- Remington 700 footprint
- Three-lug bolt design
- 60-degree bolt throw
- M16-style extractor
- One-piece .718″ diameter bolt body
- Wire EDM raceways for consistent tolerances and smooth cycling
- Pinned 20 MOA Picatinny rail
- Large ejection port
- Lightweight action-body cutout
- .062″ firing pin
- Integrated .300″ recoil lug
- Tool-less fire-control removal
- Compatible with Remington 700-pattern triggers
- 1-1/16″-16 barrel thread
- Side bolt-stop release
- Oversize bolt knob
- Spiral-fluted bolt
- Full PVD coating
- 25 oz action weight
12.5″ MÔS-Tek 338 ARC Barrel – 1:5 Twist
The CM7S uses a MÔS-Tek custom bolt-action barrel manufactured from 416R stainless steel. Chattahoochee Munitions specifies a fast 1:5 twist for our CM7S 338 ARC systems.
- 12.5″ barrel length
- 416R stainless steel
- 5R rifling
- 1:5 twist rate
- Shouldered crown
- 5/8×24 muzzle threads
- Remage barrel-nut mounting system
- E100 Blackout Cerakote
Why Chattahoochee Munitions Uses a 1:5 Twist
The standardized 338 ARC specification uses 1:8 as a practical twist-rate baseline. Chattahoochee Munitions takes a different approach with the CM7S. Based on our experience manufacturing and testing heavy .338-caliber systems, including extensive work with 8.6 Blackout, we specify a 1:5 twist for our bolt-action 338 ARC barrels.
In Chattahoochee Munitions testing, the faster twist has performed particularly well with heavy .338-caliber projectiles such as the Hornady 307-grain Sub-X. The 1:5 twist is therefore a deliberate CM specification based on the intended use of the platform rather than simply duplicating the standardized 1:8 configuration.
TriggerTech Remington 700 Primary Trigger
The 338 ARC Bolt Action SBR is equipped with a TriggerTech Remington 700 Primary trigger. Flat and curved trigger options are available, with pull weight externally adjustable from approximately 1.5 to 4.0 pounds.
TriggerTech’s Frictionless Release Technology provides a crisp break and short overtravel. Hardened 440C stainless-steel internal components provide corrosion resistance and durability, while CLKR Technology provides defined pull-weight adjustment.
WOOX Exactus Walnut Stock
The WOOX configuration replaces the standard CM7 billet chassis and telescoping stock architecture with a walnut-and-aluminum hunting platform. The Exactus stock provides traditional walnut construction combined with modern adjustability.
- Walnut construction
- Adjustable cheek riser
- Adjustable buttpad height
- Adjustable length of pull
- Bottom Picatinny rail
- QD sling mounting point
Length of pull adjusts from approximately 13.75 to 14.75 inches. Together with the adjustable cheek riser and buttpad height, the Exactus stock allows the shooter to tune the rifle’s fit while retaining the appearance and handling characteristics of a walnut hunting rifle.
WOOX Furiosa Walnut Forend
The matching WOOX Furiosa forend continues the walnut construction forward of the action while incorporating modern accessory mounting capability.
- Walnut construction
- M-LOK at the 3 o’clock position
- M-LOK at the 6 o’clock position
- M-LOK at the 9 o’clock position
WOOX Monocore and AICS Magazine System
The WOOX Monocore provides the structural interface between the CM7S action, Exactus stock, and Furiosa forend. The system uses M5-pattern bottom metal and accepts AICS-pattern detachable magazines.
Each 338 ARC Bolt Action SBR includes a 10-round MDT polymer 6 ARC AICS-pattern magazine. Chattahoochee Munitions has tested this magazine architecture with 22 ARC, 6 ARC, and 338 ARC in our bolt-action systems.
A Compact Walnut Hunting Platform
The WOOX version occupies a different role from the standard CM7 chassis configurations. At approximately 7 pounds 12 ounces, the additional weight comes with a substantially different stock and forend architecture.
The result is intended for the shooter who prefers walnut and traditional hunting-rifle ergonomics but still wants a compact barrel, detachable AICS magazine, modern action, adjustable trigger, and contemporary accessory mounting capability.
With an overall length of approximately 31.750 to 32.50 inches, the 12.5-inch WOOX configuration produces an unusually compact shoulder-fired bolt-action hunting platform.
Why a 12.5″ 338 ARC?
Barrel length is an important consideration in a compact 338 ARC system. Based on Chattahoochee Munitions testing of the loads we have evaluated, powder utilization occurs largely around the 12-inch barrel-length range.
The 12.5-inch barrel therefore provides an effective balance between ballistic efficiency and overall firearm length. Compared with the 16-inch WOOX configuration, the shorter barrel reduces overall length while retaining the same fundamental CM7S action and WOOX hunting-platform architecture.
For the shooter seeking a compact shoulder-fired bolt action rather than a pistol configuration, the 338 ARC Bolt Action SBR takes advantage of that shorter barrel while retaining the adjustable WOOX Exactus stock.
Subsonic and Supersonic Capability
The CM7S can use both subsonic and supersonic 338 ARC ammunition. Chattahoochee Munitions places particular emphasis on subsonic-capable firearm systems, and the combination of a manually operated bolt action, 12.5-inch barrel, and fast 1:5 twist makes this configuration particularly relevant to heavy .338-caliber subsonic projectiles.
Supersonic ammunition extends the useful performance envelope for applications where additional velocity is desired, allowing the same firearm architecture to support both sides of the cartridge’s performance range.
CM7S 338 ARC Bolt Action SBR Specifications
- Cartridge: 338 ARC
- Action: Chattahoochee Munitions CM7S
- Action footprint: Remington 700
- Bolt: Three-lug, 60-degree throw
- Bolt face: 6.5 Grendel Type II / .449″
- Barrel: 12.5″ MÔS-Tek 416R stainless steel
- Rifling: 5R
- Twist: 1:5
- Muzzle thread: 5/8×24
- Barrel finish: E100 Blackout Cerakote
- Trigger: TriggerTech Remington 700 Primary
- Trigger adjustment: 1.5–4.0 lb
- Stock: WOOX Exactus walnut
- Forend: WOOX Furiosa walnut
- Bottom metal: M5 / AICS compatible
- Magazine: 10-round MDT polymer 6 ARC AICS-pattern magazine
- Weight: Approximately 7 lb 12 oz
- Overall length: Approximately 31.750″–32.50″
- Length of pull: 13.75″–14.75″
Explore Containment Zone 338
This compact WOOX system is one part of the Chattahoochee Munitions 338 ARC family. Visit Containment Zone 338 to explore CM7S bolt-action firearms, CM15 AR-15 systems, barreled actions, magazines, and technical information about 338 ARC.
338 ARC Bolt Action SBR FAQ
What barrel length does the CM7S 338 ARC Bolt Action SBR use?
This configuration uses a 12.5-inch MÔS-Tek 416R stainless-steel barrel with 5R rifling and a 1:5 twist.
Why does Chattahoochee Munitions use a 1:5 twist?
CM specifies the faster twist based on our testing and experience with heavy .338-caliber projectiles and subsonic systems. In our testing, the 1:5 twist has performed particularly well with heavy projectiles such as the 307-grain Hornady Sub-X.
What makes the WOOX version different from the standard CM7S chassis?
The WOOX configuration uses an Exactus walnut stock, Furiosa walnut forend, and Monocore system with M5 bottom metal. It provides traditional walnut hunting-rifle ergonomics while retaining adjustability, detachable AICS magazine compatibility, and modern accessory mounting.
What magazine does the WOOX CM7S use?
The firearm includes a 10-round MDT polymer 6 ARC AICS-pattern magazine that Chattahoochee Munitions has tested with 338 ARC in the CM7S platform.
Can the CM7S use both subsonic and supersonic 338 ARC ammunition?
Yes. The CM7S can use both subsonic and supersonic 338 ARC ammunition. Its 1:5 twist specification is particularly oriented toward performance with heavy .338-caliber projectiles.
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