CM7S .458 SOCOM XL Barreled Action with PLACID OTB Suppressor

The CM7S .458 SOCOM XL Barreled Action with PLACID OTB Suppressor combines the heavy-projectile capability of the .458 SOCOM XL with the compact CM7S bolt-action platform and an integrated titanium over-the-barrel suppression system.

Built specifically for short-action bolt guns, the .458 SOCOM XL extends the capabilities of the .458 SOCOM concept with a 2.80-inch overall cartridge length, providing the space needed to take advantage of long, heavy .458-caliber projectiles without the dimensional limitations imposed by the AR-15 platform.

Paired with the Placid OTB suppressor, the result is a purpose-built suppressed .458-caliber system engineered around the barreled action rather than a conventional rifle with a suppressor added afterward.

Purpose-Built .458 SOCOM XL Barreled Action With Placid OTB Suppressor

The .458 SOCOM XL is designed specifically for short-action bolt-action firearms and is optimized around an overall cartridge length of 2.80 inches.

Moving beyond the dimensional restrictions of the standard .458 SOCOM and AR-15 magazine platform allows the .458 SOCOM XL to better accommodate long, heavy .458-caliber projectiles while maintaining the substantial projectile diameter and terminal capability that make the .458 SOCOM family unique.

This makes the cartridge particularly well-suited to heavy subsonic projectile applications where projectile mass, diameter, and suppressed performance are priorities.

The CM7S provides the compact short-action bolt platform needed to take full advantage of the cartridge.

Integrated PLACID OTB Suppression System

The PLACID OTB Suppressor isn’t simply a conventional suppressor attached to the muzzle. It is a purpose-built over-the-barrel suppression system engineered specifically around the CM7S.

The system uses a proprietary CM7S barrel nut featuring 1.375×24 HUB outer threads. A 12.5-inch titanium reflex tube mounts at the action and extends forward over the barrel.

At the muzzle, a 6-inch 3D-printed titanium baffle stack indexes securely against a taper mount and threads directly into the outer reflex tube.

The baffle system is specifically engineered to direct expanding gases rearward into the large-volume reflex chamber surrounding the barrel.

This makes the over-the-barrel volume an active component of the suppression system, rather than simply unused space beneath the suppressor body.

All-Titanium Construction

The complete PLACID OTB suppressor system is manufactured from titanium, including the reflex tube and 3D-printed baffle stack.

The complete suppression system measures 18.25 inches long, has a 1.5-inch diameter, and weighs just 23.6 ounces.

Its over-the-barrel architecture provides substantial internal volume while integrating the suppression system directly with the CM7S barreled action.

CM7S .458 SOCOM XL with PLACID OTB Features

• CM7S short-action bolt-action platform
• Chambered in .458 SOCOM XL
• 12.5″ 416R Stainless Barrel, 5R Rifling, 1:10 twist
• Designed around a 2.80″ overall cartridge length
• Purpose-built for short-action bolt guns
• Optimized for heavy .458-caliber projectiles
• Designed for suppressed and subsonic applications
• Integrated PLACID OTB over-the-barrel suppressor
• All-titanium suppressor construction
• 12.5″ titanium reflex tube
• 6″ 3D-printed titanium baffle stack
• Active large-volume reflex suppression chamber
• Taper-indexed muzzle interface
• Proprietary CM7S barrel nut
• 1.375×24 HUB barrel-nut interface
• 18.25″ PLACID OTB overall length
• 1.5″ suppressor diameter
• 23.6 oz PLACID OTB weight
• 4 lb 15.7 oz complete barreled action with PLACID OTB

.458 SOCOM XL — Built Beyond the AR-15 Envelope

The .458 SOCOM XL takes the fundamental advantages of a large-bore .458-caliber cartridge and moves them into a platform where AR-15 magazine length is no longer the limiting factor.

With its 2.80-inch overall cartridge length and CM7S short-action bolt platform, the cartridge can take advantage of long, heavy projectiles particularly well suited to subsonic applications.

Adding the PLACID OTB suppressor completes the concept.

Instead of building the barreled action first and attaching a conventional suppressor afterward, the CM7S .458 SOCOM XL Barreled Action with PLACID OTB integrates the action, barrel, and suppression system into a single purpose-built platform.

For shooters seeking a suppressed .458 SOCOM XL bolt-action system centered around heavy projectiles, substantial bore diameter and subsonic performance, the CM7S with PLACID OTB provides a foundation engineered specifically for that role.

PLACID OTB Suppressor — Over-the-barrel suppression engineered around the CM7S.

Frequently Asked Questions

What is .458 SOCOM XL?

.458 SOCOM XL is a bolt-action-focused evolution of .458 SOCOM designed around a 2.802″ overall cartridge length. The additional cartridge length allows the use of exceptionally heavy .458-caliber projectiles without the dimensional limitations imposed by the AR-15 magazine.

Can .458 SOCOM XL be used in a standard .458 SOCOM firearm?

No. .458 SOCOM XL is designed specifically for appropriately chambered short-action bolt-action firearms. It should not be used in standard .458 SOCOM firearms, AR-15 platforms, mini actions, or firearms not specifically chambered for .458 SOCOM XL.

Is the CM7S .458 SOCOM XL designed primarily for subsonic ammunition?

Yes. The CM7S .458 SOCOM XL platform is purpose-built around heavy subsonic .458-caliber projectiles and suppressed operation.

What is the PLACID OTB Suppressor?

PLACID OTB suppressor is Chattahoochee Munitions’ purpose-built over-the-barrel/reflex suppression system for the CM7S. Instead of placing the entire suppressor forward of the muzzle, a substantial portion of the suppressor extends rearward over the barrel.

Is PLACID OTB just a conventional suppressor mounted to the barrel?

No. PLACID OTB is engineered around the CM7S action and barrel system. Its proprietary CM7S barrel nut provides the mounting interface for the titanium reflex tube, while the muzzle-mounted baffle stack vents expanding gases rearward into the surrounding reflex chamber.

The over-the-barrel volume is therefore an active part of the suppression system, rather than simply an outer sleeve.

How long is the PLACID OTB Suppressor?

The complete PLACID OTB suppression system is 18.25 inches long. It consists of a 12.5-inch titanium reflex tube section and a 6-inch 3D-printed titanium baffle stack at the muzzle end.

How much does the PLACID OTB Suppressor weigh?

The complete PLACID OTB system weighs 23.6 oz. and is constructed entirely from titanium.

How much does the complete CM7S barreled action with PLACID OTB weigh?

The complete CM7S barreled action with PLACID OTB weighs 4 lb 15.7 oz.

What mounting system does PLACID OTB use?

PLACID OTB Suppressor integrates with the CM7S through a proprietary barrel nut featuring 1.375×24 HUB outer threads. The 3D-printed titanium baffle stack indexes at the muzzle using a taper mount and incorporates external 1.375×24 HUB threads to interface with the outer reflex tube.

Why use an over-the-barrel suppressor for .458 SOCOM XL?

Heavy subsonic .458-caliber ammunition produces a substantial volume of expanding gas. The PLACID OTB architecture provides significant internal volume while positioning much of that volume rearward over the barrel rather than placing the entire suppressor forward of the muzzle.

This architecture is particularly well suited to the design objectives of the .458 SOCOM XL CM7S platform.

Is the PLACID OTB removable?

Yes. PLACID OTB is a dedicated suppression system engineered around the CM7S, but its components are removable rather than being permanently integral to the barreled action.

Does the PLACID OTB require an NFA transfer?

Yes. The PLACID OTB is a firearm suppressor and is subject to applicable federal, state, and local laws and transfer requirements.

What makes this different from a conventional suppressed .458 SOCOM bolt gun?

The difference is that the cartridge, CM7S barreled action, and PLACID OTB suppression system were selected and engineered to function as a unified platform.

.458 SOCOM XL provides the cartridge length needed for extremely heavy .458-caliber projectiles. The CM7S provides the short-action bolt platform. PLACID OTB provides a large-volume titanium suppression system built around that barreled action.

CM7S + .458 SOCOM XL + PLACID OTB — one integrated system built for maximum subsonic capability.