CM7S 8.6 Blackout 8″ Barreled Action

Chattahoochee Munitions manufactures this 8.6 Blackout short barreled action: a CM7S bolt action with a Remington 700 footprint, fitted and headspaced to an 8-inch Mos-Tek 416R stainless 8.6 Blackout barrel in a 1:3 or 1:5 twist. Add a chassis, a trigger and a magazine to finish the firearm.

See complete CM7S firearms and every other 8.6 Blackout configuration in Area 8.6, and read What Is 8.6 Blackout? if the cartridge is new to you.

Why an 8.6 Blackout Short Barreled Action

An 8.6 Blackout short barreled action with an 8-inch barrel keeps a suppressed Remington 700 footprint host compact. It trades some subsonic velocity for length.

Fitted to a stock, it makes a short-barreled rifle under the NFA; fitted to a brace, a pistol. Follow federal, state and local law for the configuration you assemble.

CM7S Action

The CM7S action has a Remington 700 short-action footprint, three locking lugs, a 60-degree bolt throw, an M16-style extractor, a one-piece .718-inch spiral-fluted bolt, wire EDM raceways, a pinned 20 MOA Picatinny rail, an integrated .300-inch recoil lug, tool-less fire-control removal, a side bolt release and a full PVD coating. The action alone weighs about 25 oz. It accepts Remington 700-pattern triggers.

8-Inch Barrel and 1:3 or 1:5 Twist

The 8-inch barrel is made by Mos-Tek from 416R stainless steel with 5R rifling, finished in E100 Blackout Cerakote, with a shouldered crown, 5/8×24 muzzle threads and a Remage barrel nut. In Chattahoochee Munitions testing with barrels of about 12.5 inches and longer, the 1:5 twist suits bullets of about 300 gr and lighter, and the 1:3 twist suits heavy subsonic bullets of about 323 gr and heavier. Choose the twist for the bullet you plan to shoot. An 8-inch barrel gives lower velocity than those test barrels. Read 8.6 Blackout twist rate and 8.6 Blackout barrel length.

Finish the Firearm

Chattahoochee Munitions sells the parts used on its complete CM7S firearms: the CM7S Bolt Action Chassis (billet aluminum, AICS-pattern magazine well, M-LOK, QD sockets and a full-length ARCA rail), the TriggerTech R700 Primary trigger from TriggerTech, the CM Vertical Precision Crossover Grip and the 10-round 8.6 Blackout magazine. A barreled action does not include a trigger, chassis or magazine.

Suppressor and Ammunition

Chattahoochee Munitions recommends an enclosed suppressor rated for .338 caliber or larger on a CM7S, such as the PLACID 375; the bolt does not cycle when it fires, so the action adds no noise. Chattahoochee Munitions does not load 8.6 Blackout ammunition; Just Cause USA and Black Butterfly sell subsonic loads. Read 8.6 Blackout ammo and the 8.6 Blackout suppressor guide.

Prefer a finished firearm? See the 8-inch 8.6 Blackout compact bolt action and the 12.5-inch 8.6 Blackout barreled action. Compare the cartridge in 375 Raptor vs 8.6 Blackout and 338 ARC vs 8.6 Blackout.

8.6 Blackout Short Barreled Action Specifications

• Manufacturer: Chattahoochee Munitions
• Platform: CM7S bolt action
• Chambering: 8.6 Blackout
• Action: Remington 700 short-action footprint, three locking lugs, 60-degree throw, full PVD coating
• Optic rail: Pinned 20 MOA Picatinny
• Bolt face: .308 Winchester family (.473-inch)
• Barrel: 8-inch Mos-Tek 416R stainless steel, 5R rifling
• Twist rate: 1:3 or 1:5
• Barrel finish: E100 Blackout Cerakote
• Muzzle: 5/8×24 threads, shouldered crown
• Barrel interface: Remage barrel nut
• Trigger: Not included; accepts Remington 700-pattern triggers
• Weight: 49.21 oz (3.07 lb), barreled action; the listing weight is for shipping

8.6 Blackout Short Barreled Action FAQ

Who makes an 8.6 Blackout Short Barreled Action?

Chattahoochee Munitions manufactures this CM7S barreled action with an 8-inch Mos-Tek 416R stainless barrel.

What is included?

The CM7S action with its bolt and pinned 20 MOA rail, and the barrel installed and headspaced. A trigger, chassis and magazine are not included.

Does it fit Remington 700 stocks and chassis?

The CM7S has a Remington 700 short-action footprint. Confirm fit with the maker of your stock or chassis; the CM7S Bolt Action Chassis is made for it.

What trigger does it take?

Remington 700-pattern triggers. Complete CM7S firearms use the TriggerTech R700 Primary, adjustable from 1.5 to 4.0 lb.

What magazine does it use?

AICS-pattern short-action magazines in a compatible chassis or bottom metal, such as the CM7S 8.6 Blackout magazine.

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

Choose 1:3 for heavy subsonic bullets of about 323 gr and up, and 1:5 for bullets of about 300 gr and lighter. Those are Chattahoochee Munitions observations from barrels of about 12.5 inches and longer.

What suppressor should I use?

An enclosed suppressor rated for .338 caliber or larger. The barrel has 5/8×24 threads.

Is it an NFA item?

The barreled action on its own is not. Fitting the 8-inch barreled action to a stock makes a short-barreled rifle, which needs an approved ATF Form 4 before you assemble it.