Daniel Defense DDM4ISR - .300 BLK. The DDM4ISR is an integrally suppressed rifle that uses a non-removable suppressor that fits partially over the 9" barrel for a total 16" length. It also sports a unique keymod handguard not seen on any other Daniel Defense offering.. Daniel Defense - DDM4 ISR, 300 BLK, 9", MFR XL 15.0 Rail, Integrated Suppressor, Brown MilSpec+, 32-rd Technical Specifications Caliber: 300 BLACKOUT Barrel Length: 9.000" Finish: MSpec+ Brown Action Type: Semi Auto Stock/Grip: Collapsible Sights: Optics Rail Capacity: 32 NFA. The Daniel Defense DDM4ISR is our Integrally Suppressed Weapon System optimized for the .300 Blackout cartridge. Built around a 9″, Cold Hammer Forged barrel that is fluted along with a target crown and a standard pistol-length gas system, this versatile, high-performance rifle is the complete package, accurately delivering both subsonic and supersonic projectiles downrange with unrelenting reliability.. "/>Daniel defense ddm4 isr