Daniel Defense DDM4 300S 10.3 in .300 AAC Blackout Upper

The Daniel Defense DDM4 300S is a complete upper receiver built for AR-platform rifles chambered in .300 AAC Blackout. It pairs a compact 10.3 inch barrel with a 1:8 twist rate and the DDM4 Rail 9.0 to provide a short, robust package for maneuverable configurations. Construction and finish are consistent with Daniel Defense manufacturing and intended for standard AR rifle fitment.

Key Specifications

• Chambering is .300 AAC Blackout.
• The barrel measures 10.3 inches.
• Barrel twist rate is 1:8.
• Rail configuration is a DDM4 Rail 9.0.
• Gas system uses a pistol-length gas system.
• Includes a Grip-N-Rip charging handle.
• Barrel is threaded with a 1/2x28 muzzle thread pattern.
• Finish is Matte Black.
• Overall weight is approximately 3.65 lbs..
• Designed as a complete upper receiver for AR rifles.

This DDM4 300S upper provides a compact, well-equipped option for short-barrel AR builds where a reduced overall length and robust rail system are priorities. Its combination of a 10.3 inch barrel, threaded muzzle, and DDM4 Rail 9.0 offers a practical balance of form and function for precision-minded shooters seeking a durable, ready-to-install upper component.