A suppressed bolt action rifle takes the action out of the noise for a simple reason: the action does not cycle when it fires, so what is left to manage is the muzzle blast and, with supersonic ammunition, the bullet. Pair it with subsonic ammunition and an enclosed suppressor and you remove the supersonic crack too. Chattahoochee Munitions manufactures the CM7S suppressed bolt action rifle as a 12.5-inch SBR with the all-titanium PLACID OTB, in 375 Raptor and 458 SOCOM XL.
Why a Suppressed Bolt Action Rifle
Three things decide how a suppressed firearm sounds: the ammunition, the action and the suppressor.
- Ammunition: a subsonic bullet, below roughly 1,050 to 1,125 fps depending on temperature, makes no sonic crack in flight.
- Action: a bolt action stays closed until you open it, so there is no bolt noise, no gas blowing back toward your face, and no back pressure to tune for.
- Suppressor: Chattahoochee Munitions recommends an enclosed suppressor on every bolt action.
A semi-auto can be suppressed well, but it adds action noise and cycles gas through the action. A bolt action removes both.
Subsonic Loads for a Suppressed Bolt Action Rifle
Below the speed of sound, energy comes from bullet weight, so heavy-bullet cartridges suit this setup.
| Cartridge | Chattahoochee Munitions subsonic load | From 12.5 inches | Energy |
|---|---|---|---|
| 375 Raptor (designed by Arne Brennan) | 400 gr Maker REX | About 1,016 fps | About 917 ft-lb muzzle, 842 ft-lb at 100 yards |
| 458 SOCOM XL | 650 gr Maker REX, 2.802 inches overall | About 1,010 fps | About 1,473 ft-lb muzzle, 1,342 ft-lb at 100 yards |
Both loads are developed in a 12.5-inch barrel, so a short barrel gives up little and keeps the rifle handy. Read 375 Raptor subsonic and 458 SOCOM subsonic.
The CM7S With PLACID OTB
The 375 Raptor suppressed SBR and the 458 SOCOM suppressed SBR share one layout: a CM7S steel action with a Remington 700 footprint, an unported 12.5-inch Mos-Tek 416R barrel, a TriggerTech Remington 700 Primary trigger, the CM7 billet aluminum chassis, and the PLACID OTB.
- Suppressor: PLACID OTB, all titanium, 17.25 inches long on 375 Raptor and 18.25 inches on 458 SOCOM XL, 12.5-inch reflex tube over the barrel, baffle stack past the muzzle (5 inches on 375 Raptor, 6 inches on 458 SOCOM XL), 23.6 oz
- Overall length: 30.00 to 37.625 inches (375 Raptor) or 31.00 to 38.625 inches (458 SOCOM XL) with the suppressor installed
- Weight: 7 lb 13.6 oz
- Twist: 1:8 for 375 Raptor, 1:10 for 458 SOCOM
- Finish: Choice of nine Cerakote colors, including Cobalt Kinetics Green Cerakote, with Black or Coyote furniture
Because 12.5 inches of the PLACID OTB (17.25 inches on 375 Raptor, 18.25 inches on 458 SOCOM XL) wrap around the barrel, only the baffle stack extends past the muzzle: 5 inches on 375 Raptor and 6 inches on 458 SOCOM XL. Read reflex suppressor for how it works.
Is It an Integrally Suppressed Bolt Action Rifle?
No. An integrally suppressed rifle has the suppressor made as part of the barrel, often with ported bores. The PLACID OTB is a separate over the barrel suppressor on a full-length, unported barrel, and the tube and baffle stack thread off for service. You get the short package without porting the barrel.
Other Ways to Suppress a 375 Raptor Bolt Action
If you prefer a conventional suppressor, a CM7S 375 Raptor with an 11/16×24 muzzle pairs with the PLACID 375, a direct-thread 17-4 stainless suppressor rated from 5.56 NATO through .375 Magnum. It is 8.25 inches long and 16.9 oz. Compare the two in titanium vs stainless suppressor and direct thread vs HUB mount.
Hunting With a Suppressed Bolt Action Rifle
This setup suits close, quiet hunting. For feral hogs at night, a quieter report helps keep the rest of a group from scattering, and a short rifle is easy to bring up from a stand. Subsonic bullets drop quickly, so keep shots at known, moderate distances; with a 100-yard zero, the 400 gr 375 Raptor load drops about 13 inches at 150 yards. For large game, 458 SOCOM XL carries over 1,300 ft-lb at 100 yards and is suited to black, brown and grizzly bear. Read 375 Raptor hunting and 458 SOCOM for bear.
NFA and Hearing
A 12.5-inch suppressed bolt action rifle is both a short-barreled rifle and a suppressor under the National Firearms Act. Requirements have changed recently; check current ATF National Firearms Act guidance and your state law, and see NFA Firearms. A suppressed rifle is not silent, so wear hearing protection.
Suppressed Bolt Action Rifle FAQ
Who makes a suppressed bolt action rifle?
Chattahoochee Munitions manufactures the CM7S 375 Raptor and 458 SOCOM XL suppressed SBRs, 12.5-inch bolt action rifles with the all-titanium PLACID OTB over the barrel suppressor, plus matching suppressed barreled actions.
Why is a bolt action quieter than a semi-auto when suppressed?
The bolt stays closed when the rifle fires, so there is no action noise and no gas cycling back through the action.
Do I need subsonic ammunition?
To remove the sonic crack, yes. The 375 Raptor 400 gr and 458 SOCOM XL 650 gr loads both stay below the speed of sound from a 12.5-inch barrel.
Which suppressor should I use on a bolt action?
An enclosed suppressor. Chattahoochee Munitions recommends enclosed suppressors on every CM7S.
How long is the CM7S with PLACID OTB?
30.00 to 37.625 inches overall on 375 Raptor and 31.00 to 38.625 inches on 458 SOCOM XL, with the suppressor installed.
Is the PLACID OTB integrally suppressed?
No. It is a separate reflex suppressor on an unported barrel.
Can I buy the barreled action instead?
Yes. The 375 Raptor suppressed barreled action and 458 SOCOM suppressed barreled action each weigh 4 lb 15.7 oz with the PLACID OTB.