CM7S 338 ARC 16″ Barreled Action

CM7S 338 ARC Barreled Action – 16″

The Chattahoochee Munitions 338 ARC Barreled Action combines the CM7S Remington 700-footprint action with a 16-inch, 1:5 twist 338 ARC barrel. It provides the core of a purpose-built bolt-action 338 ARC system while allowing the customer to select the stock or chassis, trigger, bottom metal, and other components appropriate for the finished rifle.

Chattahoochee Munitions builds extensively with heavy .338-caliber projectiles and subsonic cartridges. That experience influences how we configure 338 ARC. Rather than simply duplicating the standardized 1:8 twist specification, the CM7S uses a 1:5 twist across our 338 ARC bolt-action lineup, including this 16-inch configuration.

For shooters building around a conventional rifle-length barrel, this 338 ARC Barreled Action provides a ready foundation without requiring the purchase of a complete firearm.

CM7S Action – Full PVD Coated

At the center of the system is the Chattahoochee Munitions CM7S action. The CM7S uses the familiar Remington 700 footprint while incorporating a three-lug bolt, 60-degree bolt throw, integrated recoil lug, M16-style extractor, and other features selected for a modern precision bolt-action platform.

• Remington 700 footprint
• 3-lug bolt design
• 60-degree bolt throw
• M16-style extractor
• One-piece .718″ diameter 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 Remington 700-pattern triggers
• 1-1/16″-16 barrel thread
• Side bolt-stop release
• Oversized bolt knob
• Spiral-fluted bolt
• Full PVD coating
• 25 oz action weight

16″ 338 ARC Barrel

The 338 ARC Barreled Action is fitted with a 16-inch stainless-steel barrel manufactured for Chattahoochee Munitions by MÔS-Tek. The barrel uses 5R rifling and a 1:5 twist, is finished in E100 Blackout Cerakote, and uses the Remage barrel-nut system.

• 16″ barrel length
• 416R stainless steel
• 5R rifling
• 1:5 twist rate
• Shouldered crown
• 5/8×24 muzzle threads
• Remage barrel-nut system
• E100 Blackout Cerakote

Complete barreled-action weight: 62.81 oz / 3.92 lb

Weights and dimensions shown elsewhere in the product data may represent shipping dimensions rather than the physical dimensions of the barreled action.

Why CM Uses a 1:5 Twist in the 338 ARC Barreled Action

SAAMI standardized 338 ARC with a 1:8 right-hand twist as an optional rifling specification. Chattahoochee Munitions takes a different approach with its CM7S bolt-action systems.

Based on our experience manufacturing and testing firearms using heavy .338-caliber projectiles, CM specifies a 1:5 twist for the entire CM7S 338 ARC lineup. In our testing and experience, the faster twist has performed particularly well with heavy projectiles such as the 307-grain Hornady Sub-X.

This is especially relevant for shooters considering a 338 ARC Barreled Action as the foundation of a subsonic or suppressed bolt-action system.

Why a 16″ 338 ARC Barreled Action?

The 16-inch configuration provides a conventional rifle-length option within the CM7S 338 ARC family. It is particularly appropriate for a customer who wants to build a rifle without starting with a short barrel.

More barrel length should not automatically be interpreted as dramatically greater 338 ARC performance. In Chattahoochee Munitions’ experience with the loads and configurations we have evaluated, much of the useful powder utilization occurs around the 12-inch range. The 16-inch configuration therefore serves primarily as a conventional-length option rather than being positioned as necessary for the cartridge to perform effectively.

Customers prioritizing a shorter overall system can also choose the 12.5-inch or 8-inch CM7S configurations.

338 ARC in a Bolt-Action Platform

Although 338 ARC was designed to fit within the AR-15 cartridge envelope, it also makes an interesting bolt-action cartridge. A manually operated action removes the requirement to use propellant gas to cycle a semi-automatic operating system, allowing the rifle to be configured around a different set of priorities.

The CM7S 338 ARC Barreled Action uses a 6.5 Grendel Type II .449″ bolt face and is designed around an AICS-pattern magazine system when installed in a compatible finished rifle.

Chattahoochee Munitions has already tested and selected the magazine used in our complete CM7S 338 ARC rifles. Our 338 ARC Bolt Action Magazine is a 10-round MDT polymer AICS-pattern magazine tested by CM with 338 ARC.

A Foundation for a Custom 338 ARC Rifle

A barreled action allows the customer to start with the action, bolt, barrel, barrel nut, and rail already configured around the cartridge while retaining control over the rest of the rifle.

The Remington 700 footprint provides access to a broad ecosystem of compatible stocks, chassis systems, triggers, and related components. The CM7S accepts Remington 700-pattern triggers and uses a Remage barrel-nut architecture.

This makes the 338 ARC Barreled Action particularly useful for a shooter who wants CM’s 338 ARC barrel and action configuration without being locked into the chassis and furniture of a complete CM7S firearm.

338 ARC Subsonic Applications

Heavy subsonic ammunition is an important part of the 338 ARC performance envelope and one of the reasons Chattahoochee Munitions offers the cartridge in the CM7S platform.

Projectile weight, twist rate, barrel length, ammunition selection, and suppressor configuration all affect the resulting system. The bolt-action platform also removes the need to balance ammunition performance against the gas requirements of a semi-automatic action.

For a deeper discussion of the cartridge, including barrel length, 1:8 versus 1:5 twist, suppression, and comparisons with 300 Blackout and 8.6 Blackout, read our 338 ARC Subsonic technical guide.

Explore Containment Zone 338

The 16-inch barreled action is one part of the broader Chattahoochee Munitions 338 ARC lineup. CM offers 338 ARC across bolt-action and AR-15 platforms, including complete rifles, compact configurations, barreled actions, upper receivers, and tested magazines.

Explore the complete lineup in Containment Zone 338.

338 ARC Barreled Action FAQ

What is included in a 338 ARC Barreled Action?

The CM7S 338 ARC Barreled Action combines the CM7S Remington 700-footprint action with a chambered 338 ARC barrel and associated barrel hardware. It provides the core assembly for building a complete bolt-action rifle around the customer’s choice of compatible components.

What twist rate does the CM7S 338 ARC use?

Chattahoochee Munitions uses a 1:5 twist in its CM7S 338 ARC barrels, including the 16-inch version. This specification reflects CM’s experience with heavy .338-caliber projectiles and subsonic applications.

Does the CM7S use a Remington 700 footprint?

Yes. The CM7S action uses a Remington 700 footprint and accepts Remington 700-pattern triggers, providing access to a broad selection of compatible components for custom rifle builds.

What magazine does a completed CM7S 338 ARC use?

CM7S 338 ARC rifles use an AICS-pattern magazine system. Chattahoochee Munitions uses a tested 10-round MDT polymer magazine for its complete CM7S 338 ARC firearms.

Is 338 ARC suitable for subsonic use?

Yes. Heavy subsonic ammunition is an important part of the cartridge’s performance envelope. Chattahoochee Munitions’ CM7S configuration uses a 1:5 twist based on our experience with heavy .338-caliber projectiles.

Does Chattahoochee Munitions offer shorter 338 ARC barreled actions?

Yes. In addition to this 16-inch 338 ARC Barreled Action, Chattahoochee Munitions offers 12.5-inch and 8-inch CM7S barreled-action configurations for customers prioritizing a more compact system.