CM10 243 Winchester 20″ AR10 Rifle – Black Tungsten

243 Semi Auto Rifle — CM10 Black Tungsten

The 243 Semi Auto Rifle from Chattahoochee Munitions brings the established 243 Winchester cartridge to the CM10 large-frame semi-automatic platform. This Black Tungsten configuration combines CNC-machined billet receivers, a 20-inch barrel, TriggerTech Duty trigger, and rifle-length adjustable gas system.

Customers can select between two barrel configurations: a 1:8 twist 416R stainless steel SOCOM/HBAR barrel or a 1:10 twist 4150 CrMV medium-profile barrel.

Part of Predator Plains — High Velocity Systems, the CM10 243 Winchester joins the CM high-velocity cartridge lineup designed around predator hunting, varmint applications, and precision shooting.

CM10 243 Semi Auto Rifle — Billet Receiver System

The CM10 upper and lower receivers are CNC-machined from 7075-T6 billet aluminum. The receiver architecture follows applicable DPMS high-profile AR10-pattern component specifications.

Upper and Lower Receiver Specifications

• Platform: CM10 Large-Frame Semi-Automatic
• Receiver Material: 7075-T6 Billet Aluminum
• Receiver Pattern: DPMS High Profile
• Barrel Nut Interface: 16 TPI
• Upper Receiver: Lightweight Machined Profile Without Forward Assist
• Lower Receiver: Machined Magazine Well with Wide Flare
• Trigger Guard: Integral
• Safety Markings: Pictogram Fire/Safe Engravings on Both Sides
• Receiver Finish: Black Tungsten Cerakote

243 Semi Auto Rifle — Two Barrel Configurations

The CM10 243 Winchester offers two distinct 20-inch barrel options. Each configuration uses a different combination of barrel material, contour, and twist rate.

Option 1 — 1:8 Twist Stainless Steel Barrel

• Chambering: 243 Winchester
• Barrel Length: 20 inches
• Material: 416R Stainless Steel
• Profile: SOCOM/HBAR
• Twist Rate: 1:8
• Muzzle Threads: 5/8×24
• Gas Journal: .750 inch
• Finish: Tactical Grey Cerakote

Option 2 — 1:10 Twist CrMV Barrel

• Chambering: 243 Winchester
• Barrel Length: 20 inches
• Material: 4150 CrMV
• Profile: Medium
• Twist Rate: 1:10
• Muzzle Threads: 5/8×24
• Gas Journal: .750 inch
• Finish: Tactical Grey Cerakote

Twist rate is one factor in projectile stabilization. Bullet length, construction, velocity, and environmental conditions also affect the suitability of a specific projectile for either configuration.

TriggerTech Duty Trigger and CM10 Lower Components

The 243 Semi Auto Rifle includes a TriggerTech Duty trigger with three selectable configurations. Each option provides a 3.5 lb total pull weight.

• Trigger: TriggerTech AR Duty
• Option 1: Single-Stage Flat — 3.5 lb
• Option 2: Single-Stage Curved — 3.5 lb
• Option 3: Two-Stage Flat — 3.5 lb Total
• Safety: CM Ambidextrous Safety Selector
• Magazine Release: CM Ambidextrous
• Bolt Release: CM10 Ambidextrous
• Pins: CM10 Pivot and Takedown Pins
• Pistol Grip: B5 Systems Black

B5 Systems Stock and Adjustable Buffer

The Black Tungsten CM10 features Black B5 Systems furniture and a receiver extension finished in matching Black Tungsten Cerakote.

• Stock: B5 Systems CPS Medium — Black
• Pistol Grip: B5 Systems — Black
• Rail Covers: B5 Systems — Black
• Receiver Extension: CM Mil-Spec Buffer Tube
• Receiver Extension Finish: Black Tungsten Cerakote
• Buffer: Odin Adjustable Buffer AR10
• Endplate: Quick-Detach Configuration

CM10 Bolt Carrier Group

The CM10 features a bolt carrier group with the following construction and component specifications:

• 9310 Steel Bolt
• High-Pressure Tested (HPT) Bolt
• Magnetic Particle Inspected (MPI) Bolt
• Shot-Peened Bolt
• Nitride-Coated Bolt and Carrier
• Nitride-Coated Gas Key
• Gas Key Hardened to USGI Specifications
• Grade 8 Hardened Gas Key Fasteners
• Staked Gas Key Fasteners
• Tool Steel Extractor
• T.E.A. Extractor Spring
• Black Extractor Insert
• Crane-Pattern O-Ring

Rifle-Length Gas System and 15-Inch Handguard

The CM10 243 Semi Auto Rifle features a rifle-length gas system with a Superlative Arms .750 adjustable gas block and an Odin Adjustable Buffer. Superlative Arms provides technical documentation explaining the operation and adjustment features of its gas block systems.

The 15-inch CM10 LWS M-LOK handguard is finished in Black Tungsten Cerakote to match the upper and lower receivers and buffer tube.

• Charging Handle: CM10 Ambidextrous, 7075 Aluminum
• Gas System: Rifle-Length
• Gas Tube: CM Rifle-Length, Melonite Finish
• Gas Block: Superlative Arms .750 Adjustable, Melonite Finish
• Handguard: CM10 LWS 15-Inch M-LOK
• Handguard Material: 6061 Aluminum
• Handguard Finish: Black Tungsten Cerakote
• Barrel Nut: Steel
• Top Rail: Full-Length Picatinny
• Accessory Interface: M-LOK Mounting Positions
• QD Attachment: 3 and 9 O’Clock Positions
• Rail Covers: B5 Systems Black

Muzzle-device selections are available through the product configuration menu. The muzzle device shown in product photographs may differ from the selected configuration.

243 Semi Auto Rifle Magazine Compatibility

The CM10 243 Winchester includes one standard 10-round Magpul PMAG 7.62 magazine.

Unlike the dedicated CM-modified magazine required for the 22-250 Remington configuration, the CM10 243 Winchester uses an unmodified PMAG 10 LR/SR GEN M3 magazine.

• Manufacturer: Magpul
• Model: PMAG 10 LR/SR GEN M3
• Capacity: 10 Rounds
• Pattern: LR/SR
• Configuration: Factory, Unmodified
• Quantity Included: One

For additional information about magazine compatibility across the high-velocity CM10 cartridge families, visit Predator Plains.

243 Semi Auto Rifle — Suppressor Considerations

For its supersonic CM10 platforms, Chattahoochee Munitions generally recommends a flow-through or low-back-pressure suppressor.

Suppressor backpressure can influence operating-system characteristics in gas-operated semi-automatic firearms. The CM10 includes a Superlative Arms adjustable gas block and Odin Adjustable Buffer as part of its operating system.

Suppressor compatibility must be confirmed against the manufacturer’s cartridge ratings, barrel-length restrictions, bore specifications, and mounting requirements.

Supersonic projectiles continue to produce a ballistic shock wave even when a suppressor is used. Appropriate hearing protection remains recommended.

CM10 Black Tungsten Dimensions and Warranty

• Overall Length: 41–43.5 inches
• Weight: 9 lb 8 oz with Unloaded Magazine
• Length of Pull: 14–17.5 inches
• Receiver Finish: Black Tungsten Cerakote
• Handguard Finish: Black Tungsten Cerakote
• Buffer Tube Finish: Black Tungsten Cerakote
• Furniture Color: Black
• Warranty: Chattahoochee Munitions Limited Lifetime Warranty

Published product dimensions and weight describe the rifle configuration. Shipping dimensions and shipping weight shown elsewhere on the product page may differ.

The limited lifetime warranty applies to the original purchaser, subject to Chattahoochee Munitions’ published warranty terms and exclusions.

243 Semi Auto Rifle — Cartridge Education

The 243 Winchester is an established .243-caliber centerfire cartridge used in hunting and precision shooting applications. Its long history and common ammunition availability make it a familiar chambering among hunters and recreational shooters.

The newer 6mm Creedmoor shares the same nominal projectile diameter but differs in case geometry and common rifle configurations.

Read our 6mm Creedmoor vs 243 Winchester Comparison for a closer look at the two cartridges.

Explore the complete Predator Plains — High Velocity Systems collection for additional CM10 chamberings and cartridge guides.

Frequently Asked Questions About the CM10 243 Semi Auto Rifle

What barrel options are available for the CM10 243 Semi Auto Rifle?

The CM10 offers two 20-inch barrel configurations: a 1:8 twist 416R stainless steel SOCOM/HBAR barrel and a 1:10 twist 4150 CrMV medium-profile barrel. Both have 5/8×24 muzzle threads, a .750 gas journal, and Tactical Grey Cerakote.

Does the CM10 243 Winchester require a modified magazine?

No. The CM10 243 Winchester includes a standard, unmodified Magpul PMAG 10 LR/SR GEN M3 magazine.

What TriggerTech options are available?

The rifle offers TriggerTech Duty single-stage flat, single-stage curved, and two-stage flat configurations. All three have a 3.5 lb total pull weight.

Does the CM10 have an adjustable gas system?

Yes. The rifle uses a rifle-length gas system with a Superlative Arms .750 adjustable gas block and an Odin Adjustable Buffer.

What finish is used on the Black Tungsten configuration?

The upper and lower receivers, 15-inch handguard, and buffer tube receive matching Black Tungsten Cerakote. The B5 Systems stock, pistol grip, and rail covers are Black.

What suppressor type does CM recommend?

Chattahoochee Munitions generally recommends a compatible flow-through or low-back-pressure suppressor for its supersonic CM10 rifles, subject to the suppressor manufacturer’s specifications.

Where can I compare 243 Winchester and 6mm Creedmoor?

Visit our 6mm Creedmoor vs 243 Winchester Guide for a detailed cartridge comparison.