Daniel Defense DDM4 300 Pistol with 10.3 inch CHF Barrel

Product Description

The Daniel Defense DDM4 300 Pistol pairs proven MK18 platform engineering with the hard-hitting .300 AAC Blackout cartridge. This 10.3-inch cold-hammer-forged barrel delivers reliable performance in a compact, maneuverable package. The RIS II handguard provides extensive rail real estate for lights, lasers, and accessories.

Additionally, every Daniel Defense firearm is hand assembled and quality assurance tested before it ships. Each pistol is also test fired to ensure reliability and accuracy. This commitment to precision manufacturing means you receive a battle-proven platform backed by Daniel Defense’s reputation.

Furthermore, the 1:7 twist rate stabilizes both supersonic and subsonic .300 Blackout loads effectively. The pistol ships factory-equipped with an SB Tactical SBA3 adjustable stabilizing brace. This configuration delivers the handling of a pistol with enhanced control and stability.

Materials & Construction

• Lower Receiver: Daniel Defense Lower Receiver, CNC Machined of 7075-T6 Aluminum, Type III Hard Coat Anodized, with Enhanced Flared Magazine Well and Forward Receiver QD Sling Swivel Attachment Point
• Upper Receiver: Mil-Spec with Indexing Marks and M4 Feed Ramps, CNC Machined of 7075-T6 Aluminum, Type III Hard Coat Anodized
• Barrel: 10.3″ Government Profile, Chrome Moly Vanadium Steel, Cold Hammer Forged, 1:7 Twist Tuned for .300 Blackout, Chrome Lined, Mil-Spec Heavy Phosphate Coated, HP/MPI Tested
• Gas System: Pinned Low-Profile Gas Block, CNC Machined of 4140 Hardened Steel, Mil-Spec Heavy Phosphate Coating, Pistol-Length, Direct Impingement
• Muzzle Device: Daniel Defense Flash Suppressor, 17-4 PH Stainless Steel, Salt Bath Nitride Finished, 5/8×24 TPI Threads
• Handguard: Daniel Defense RIS II MK18, CNC Machined of 6061-T6 Aluminum, Type III Hard Coat Anodized, Picatinny Top Rail with KeyMod at 3/6/9 o’clock, Santoprene Rail Panels
• Bolt Carrier Group: M16 Profile Bolt Carrier Group, Mil-Spec MP Tested, Chrome Lined, with Properly Staked Gas Key
• Charging Handle: Daniel Defense GRIP-N-RIP Charging Handle — Body CNC Machined of 7075-T6 Aluminum, Handles & Latch CNC Machined of 6061-T6 Aluminum, Heavy Duty Stainless Steel Roll Pins, Type III Hard Coat Anodized
• Pistol Grip: Daniel Defense Pistol Grip, Glass-Filled Polymer with Soft-Touch Overmolding and Internal Storage Compartment
• Stabilizing Brace: SB Tactical SBA3 Pistol Stabilizing Brace, Adjustable Across 5 Positions, Mounted on Daniel Defense’s 1.15″ Diameter Pistol Receiver Extension

Specifications

This pistol ships from the factory with an SB Tactical pistol stabilizing brace attached to a pistol-length receiver extension, configured as a firearm — not a rifle. A 2024 federal court ruling vacated ATF’s 2023 rule that reclassified braced pistols as Short-Barreled Rifles (SBRs), and the government dropped its appeal of that ruling in 2025. As a result, a stabilizing brace alone no longer causes a pistol to be treated as an SBR under the National Firearms Act (NFA). As of 2026, ATF has proposed formally removing the old ‘redesigned to be fired from the shoulder’ factoring criteria, with public comments open through August 4, 2026. As configured and shipped, this pistol requires no NFA registration or tax stamp — only the standard ATF Form 4473 background check at transfer. Permanently configuring this firearm with a shoulder stock, however, would create an SBR requiring an approved ATF Form 1 before modification. Western Sport cannot advise on individual compliance — buyers are responsible for following all applicable federal and state law.

Why Buy from Western Sport?

• Western Sport’s expert staff can answer detailed questions about .300 Blackout performance and accessory compatibility.
• We provide personalized service and honest guidance for Daniel Defense builds and configurations.
• Competitive pricing on quality Daniel Defense pistols and related components ensures real value.
• Our after-sale support includes ammunition recommendations, mounting advice, and troubleshooting assistance.

Frequently Asked Questions

Q: What ammunition performs best in the DDM4 300 Pistol?

A: Both supersonic and subsonic .300 Blackout loads work reliably. The 1:7 twist rate handles heavy subsonic rounds exceptionally well. Choose ammunition based on your intended use—hunting, suppressed shooting, or target practice.

Q: What optics and accessories mount to the RIS II handguard?

A: The RIS II features multiple rail sections compatible with standard Picatinny-mounted red dots, magnified optics, tactical lights, and laser systems. M-LOK slots also accept modern sling mounts and grip accessories. This handguard gives you endless customization options.

Q: What comes with the DDM4 300 Pistol straight from the box?

A: Your pistol ships with the SB Tactical SBA3 adjustable stabilizing brace already installed on the pistol receiver extension. You receive the firearm, one magazine, and documentation. No additional components are needed to shoot responsibly.

Q: Can I easily add or change accessories on this pistol?

A: Yes. The RIS II handguard accepts standard Picatinny rail-mounted and M-LOK accessories without gunsmithing. Moreover, the SBA3 brace is user-adjustable for length of pull. Field upgrades and customization are straightforward and fast.

Q: What is the RIS II rail system on this pistol?

A: The RIS II (Rail Interface System II) is Daniel Defense’s free-float quad-rail handguard. It features a continuous top Picatinny rail for optics and sights. Additionally, KeyMod slots at the 3, 6, and 9 o’clock positions let you mount lights, lasers, and grips exactly where you need them.

Q: Will I need to file ATF paperwork or pay a tax stamp for this pistol’s brace?

A: No. As configured and shipped, this is a pistol with a stabilizing brace — not a Short-Barreled Rifle (SBR). ATF’s 2023 rule treating braced pistols as SBRs was vacated by federal courts in 2024, and the government dropped its appeal in 2025. Only the standard ATF Form 4473 background check applies at transfer, the same as for any other pistol.

MATERIALS & CONSTRUCTION

• LOWER RECEIVER: Mil-Spec with Enhanced Flared Magazine Well and Rear Receiver QD Swivel Attachment Point. CNC Machined of 7075-T6 Aluminum, Type III Hard Coat Anodized
• UPPER RECEIVER: Mil-Spec with Indexing Marks and M4 Feed Ramps. CNC Machined of 7075-T6 Aluminum, Type III Hard Coat Anodized
• BARREL: Chrome Moly Vanadium Steel, Cold Hammer Forged, 1:8 Twist, 10.3″ S2W Profile, Chrome Lined, Heavy Phosphate Finished, and HP/MPI Tested
• GAS SYSTEM: Pinned Low Profile Gas Block CNC Machined of 4140 hardened steel with Mil-Spec Heavy Phosphate Coating, Pistol length, Direct Impingement
• MUZZLE DEVICE: Daniel Defense Flash Suppressor, 17-4 PH Stainless Steel, Salt Bath Nitride Finished
• BOLT CARRIER GROUP: M16 Profile, Mil-Spec MP Tested, Chrome Lined, Properly Staked Gas Key
• BUFFER: H Buffer
• SIGHTS: Sold Separately
• HANDGUARD: Daniel Defense DDM4 Rail 9.0, CNC Machined of 6061-T6 Aluminum, Type III Hard Coat Anodized
• BRACE: SB-Tactical SOB Pistol Stabilizing Brace
• PISTOL GRIP: Daniel Defense Pistol Grip, Glass Filled Polymer with Soft Touch Overmolding
• RAIL PANELS: Daniel Defense Rail Panels made from Santoprene, heat resistant to 300° F
• Made in the USA!

Additional information