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. Because the suppressor is an integral part of the barrel, this weapon system is ready for service right out of the box. There's no attaching a suppressor and wondering if it's mounted correctly and/or properly aligned. There's no re-zeroing for suppressed vs. unsuppressed fire. The DDM4ISR's integral suppressor extends the barrel to an NFA-required 16 inches in length, so this platform is not classified as a Short Barreled Rifle (SBR) and therefore only requires a single tax stamp (for the suppressor).