375 Raptor Subsonic Ammo – 400gr Maker REX – Bolt Action
Chattahoochee Munitions 375 Raptor Subsonic Ammo combines the 400-grain Maker REX expanding projectile with ammunition specifically configured for bolt-action 375 Raptor firearms. This load is intended for shooters using heavy subsonic projectiles in suppressed bolt-action platforms, including Chattahoochee Munitions CM7S rifles.
Loaded with a 400-grain .375-caliber Maker REX solid copper expanding projectile, this ammunition produced an average velocity of 1,016 fps during Chattahoochee Munitions testing from a 12.5-inch barrel. The published velocity represents the average of a 10-shot chronograph sample rather than a calculated or single-shot velocity.
This bolt-action version is loaded to a 2.802-inch cartridge overall length (COAL) and is sold in 20-round boxes.
400gr Maker REX Subsonic Expanding Projectile
This 375 Raptor Subsonic Ammo is loaded with the Maker Bullets 400 Grain .375 REX projectile. Maker precision CNC machines the projectile from solid copper, providing a lead-free expanding bullet designed specifically for subsonic applications.
According to Maker Bullets, REX projectiles are engineered to expand to nearly three times their original diameter while maintaining nearly 100% of their original weight. Maker designs individual REX projectiles around specific operating velocity ranges rather than applying a single projectile design across unrelated applications.
Maker 400gr REX Projectile Specifications
- Projectile: Maker REX Subsonic Expanding
- Construction: Solid Copper, Lead Free
- Diameter: .375″
- Weight: 400 grains
- Projectile Length: 1.81″
- Sectional Density: 0.406
- Ballistic Coefficient: 0.49
- Maker Recommended Twist Rate: 1:11 or faster
1,016 FPS Average from a 12.5-Inch Barrel
Chattahoochee Munitions chronograph testing of this 375 Raptor Subsonic Ammo produced an average velocity of 1,016 fps from a 12.5-inch barrel. The reported velocity is based on a 10-round chronograph sample fired by Chattahoochee Munitions.
Actual velocity can vary between individual firearms and with barrel length, atmospheric conditions and other variables. The 1,016 fps figure should therefore be understood as a measured test result from the stated CM test configuration rather than a guaranteed velocity from every firearm.
Configured for Bolt-Action 375 Raptor Rifles
This version of 375 Raptor Subsonic Ammo is specifically configured for bolt-action firearms and is loaded to a cartridge overall length of 2.802 inches. It is appropriate for Chattahoochee Munitions CM7S rifles and other compatible bolt-action firearms properly chambered for 375 Raptor.
This load is not intended to provide reliable cycling in semi-automatic firearms. Chattahoochee Munitions offers a separate 400gr 375 Raptor subsonic load specifically configured for semi-automatic operation. Customers using a semi-automatic 375 Raptor platform should select that version instead.
Converted Starline Brass
Chattahoochee Munitions manufactures this 375 Raptor Subsonic Ammo using cases converted from Starline .358 Winchester brass. The converted cases retain the manufacturer’s original .358 WIN headstamp even though the completed ammunition is 375 Raptor ammunition.
Because the original headstamp remains visible after conversion, every customer should identify this ammunition by its packaging and intended chambering rather than by the case headstamp alone.
IMPORTANT AMMUNITION WARNING: This ammunition is manufactured using brass converted from Starline .358 Winchester cases and therefore retains a .358 WIN headstamp. The loaded ammunition is 375 Raptor ammunition. It must not be chambered or fired in a .358 Winchester firearm or any firearm not properly chambered for 375 Raptor.
375 Raptor Subsonic Ammo Specifications
- Caliber: 375 Raptor
- Projectile: Maker REX Subsonic Expanding
- Projectile Weight: 400 grains
- Projectile Diameter: .375″
- Projectile Construction: CNC-Machined Solid Copper, Lead Free
- Ballistic Coefficient: 0.49
- Sectional Density: 0.406
- Maker Recommended Twist Rate: 1:11 or faster
- Cartridge Overall Length: 2.802″
- Measured Average Velocity: 1,016 fps
- Velocity Test: 10-shot chronograph sample
- Test Barrel Length: 12.5″
- Platform: Bolt Action
- Brass: Converted Starline .358 Winchester
- Case Headstamp: .358 WIN
- Package Quantity: 20 rounds
Part of the Chattahoochee Munitions 375 Raptor System
This 375 Raptor Subsonic Ammo complements Chattahoochee Munitions bolt-action 375 Raptor firearms, including CM7S configurations equipped with the PLACID OTB suppression system. CM develops the rifle, suppression and ammunition components as parts of a complete 375 Raptor platform rather than treating ammunition as an unrelated accessory.
For additional information about 375 Raptor firearms, ammunition and related products, visit the Raptor Paddock.
Frequently Asked Questions
What projectile is used in this 375 Raptor Subsonic Ammo?
This ammunition uses the Maker Bullets 400-grain .375-caliber REX solid copper expanding projectile. Maker lists the projectile at 1.81 inches long with a 0.406 sectional density and 0.49 ballistic coefficient.
What velocity does this ammunition produce?
Chattahoochee Munitions recorded an average velocity of 1,016 fps from a 10-shot chronograph sample fired through a 12.5-inch barrel. Actual velocity can vary between firearms and operating conditions.
Is this ammunition intended for semi-automatic rifles?
No. This particular load is specifically configured for bolt-action 375 Raptor firearms and is not intended to provide reliable cycling in semi-automatic platforms. Chattahoochee Munitions offers a separate 400gr subsonic load configured for semi-automatic operation.
Why does the brass say .358 WIN?
Chattahoochee Munitions converts Starline .358 Winchester brass for use in this ammunition. The original .358 WIN headstamp remains on the converted case. Despite that headstamp, the completed cartridge is 375 Raptor ammunition and must never be fired in a .358 Winchester firearm.
What is the cartridge overall length?
This bolt-action load is manufactured to a cartridge overall length of 2.802 inches.
How many rounds are included?
Each box contains 20 rounds of 400gr 375 Raptor subsonic ammunition.
What barrel twist does Maker recommend for the 400gr REX projectile?
Maker Bullets recommends a barrel twist rate of 1:11 or faster for this projectile.
Jordan M. (verified owner) –
Initially posted a pretty scathing review on here about some incorrect 375 Raptor ammo that was sent to me, thought I had reached out to company about it, and apparently had not. My bad!
Got an email within 2 hours on a Saturday evening from Matt, who offered to fix it, and fully address the issue. That’s pretty damn awesome.
Waiting now to get it all sorted out, but it was a really awesome response time and very appreciated, considering how pissed off I was! 🤣
If it shoots right once I get it this will be the only place I buy this round from in the future. Customer service is just as important as getting good product! Especially at $4 bucks a round!