Chattahoochee Munitions manufactures this 458 SOCOM short barreled action: a CM7S bolt action with a 12.5-inch Mos-Tek 416R stainless barrel, a 1:10 twist, and E100 Blackout Cerakote. It is chambered in 458 SOCOM and configured for 458 SOCOM XL, and 12.5 inches is the barrel length the 650 gr subsonic load is developed in. Add your own Remington 700-footprint stock or chassis and trigger.
Standard 458 SOCOM is limited to 2.260 inches overall by the AR15 magazine. 458 SOCOM XL moves past that limit: the 2.035-inch, 650 gr subsonic projectile is seated less deeply, reclaiming usable case capacity for powder. See every configuration on Terminal 458.
Why a 458 SOCOM Short Barreled Action
A 458 SOCOM short barreled action starts a compact suppressed bolt action from the same action and barrel Chattahoochee Munitions uses in its 12.5-inch CM7S firearms. A subsonic load does its work early in the barrel, so the 12.5-inch barrel gives up little velocity and keeps the suppressed rifle 3.5 inches shorter than the 16-inch version.
A barrel under 16 inches makes a rifle a short-barreled rifle under the National Firearms Act, so completing this barreled action as a rifle requires an approved ATF Form 4 before you complete it; see NFA Firearms. Check your state and local laws.
CM7S Action
The CM7S action is steel with a Remington 700 footprint and a full PVD coating. It has three locking lugs, a 60-degree throw, wire EDM raceways, and a one-piece spiral-fluted bolt with a .718-inch body, an oversized knob, an M16-style extractor, and a .062-inch firing pin. Its .308-size bolt face fits the 458 SOCOM rebated rim. An integrated recoil lug and a pinned 20 MOA Picatinny rail complete the action, and the fire control removes without tools. It accepts Remington 700-pattern triggers, such as the TriggerTech Remington 700 Primary.
12.5-Inch Barrel and 1:10 Twist
The 12.5-inch barrel is made by Mos-Tek from 416R stainless steel with 5R rifling and a 1:10 twist, finished in E100 Blackout Cerakote, with a shouldered crown, 11/16×24 muzzle threads, and Remage barrel-nut mounting. Read 458 SOCOM barrel length for how the 12.5-inch and 16-inch barrels compare.
Completing the Barreled Action
The barreled action fits stocks and chassis inletted for the Remington 700 footprint, with a Remington 700-pattern trigger. To feed 458 SOCOM XL, the stock or chassis needs an AICS-pattern magazine well and the 458 SOCOM XL magazine, which is modified for XL length and is not suitable for shorter, standard 458 SOCOM loads. Chattahoochee Munitions guarantees magazine function in its complete CM7S firearms. In a rifle you assemble yourself, the stock or chassis, bottom metal, and magazine well affect feeding, so verify compatibility before use. For a complete, ready-to-shoot rifle, see the CM7S 458 SOCOM pistol or SBR and the CM7S 458 SOCOM bolt action rifle.
Ammunition
The Chattahoochee Munitions 458 SOCOM subsonic ammo for bolt action is a 650 gr Maker REX loaded to 2.802 inches. From a 12.5-inch CM7S barrel it averages about 1,010 fps and about 1,473 ft-lb at the muzzle. The barrel’s 1:10 twist stabilizes the long 650 gr bullet, where common AR15 458 SOCOM barrels use 1:14. Read 458 SOCOM ballistics and 458 SOCOM twist rate.
Suppressing the 458 SOCOM Short Barreled Action
Chattahoochee Munitions recommends an enclosed suppressor rated for .458 caliber on any CM7S. The barrel has 11/16×24 threads. The 12.5-inch barreled action is also offered with the all-titanium PLACID OTB over-the-barrel suppressor. Read the 458 SOCOM suppressor guide.
458 SOCOM Short Barreled Action Specifications
- Manufacturer: Chattahoochee Munitions
- Chambering: 458 SOCOM, configured for 458 SOCOM XL (2.802-inch cartridge overall length)
- Barrel: 12.5-inch Mos-Tek 416R stainless steel, 5R rifling
- Twist rate: 1:10
- Barrel finish: E100 Blackout Cerakote
- Muzzle: 11/16×24 threads, shouldered crown
- Barrel mounting: Remage barrel nut
- Action: Steel, Remington 700 footprint, three locking lugs, 60-degree throw, wire EDM raceways, full PVD coating, about 25 oz
- Bolt: One-piece spiral-fluted, .718-inch body, oversized knob, .308-size bolt face, M16-style extractor, side-mounted bolt stop
- Firing pin: .062-inch
- Recoil lug: Integrated
- Optic rail: Pinned 20 MOA Picatinny
- Action threads: 1-1/16-16
- Trigger: Not included; accepts Remington 700-pattern triggers, with tool-less fire-control removal
- Included: CM7S action and 12.5-inch barrel
- Not included: Stock or chassis, trigger, magazine
458 SOCOM Short Barreled Action FAQ
Who makes a 458 SOCOM short barreled action?
Chattahoochee Munitions manufactures the CM7S 458 SOCOM short barreled action with a 12.5-inch Mos-Tek 1:10 barrel, configured for 458 SOCOM XL. It is also offered with the PLACID OTB suppressor, and a 16-inch barreled action is available.
Is the CM7S a different chamber than 458 SOCOM?
No. The chamber is standard 458 SOCOM. The action is configured for 458 SOCOM XL, so it accepts the 2.802-inch, 650 gr cartridge.
Why choose the 12.5-inch barreled action over the 16-inch?
It keeps a suppressed rifle 3.5 inches shorter, and the 650 gr subsonic load is developed in 12.5-inch barrels. Completed as a rifle, it is an SBR under the NFA.
Does the barreled action include a magazine?
No. The 458 SOCOM XL magazine is sold separately. It is modified for 458 SOCOM XL and is not suitable for shorter, standard 458 SOCOM loads.
What stocks, chassis, and triggers fit the CM7S?
Stocks and chassis inletted for the Remington 700 footprint, and Remington 700-pattern triggers. To feed XL ammunition, use an AICS-pattern magazine well and verify feeding in your rifle.
What ammunition does it use?
The Chattahoochee Munitions 650 gr Maker REX subsonic load for bolt action, loaded to 2.802 inches, which averages about 1,010 fps from a 12.5-inch CM7S barrel.
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