Strategic Sciences MFMD 300 Blackout 0.0 OTB Suppressor -- MD Only 300 Blackout ? 5/8x24 Direct Thread ? 0.0 Flush Mount ? Inconel Flow-Through ? NFA The MFMD-MD is an NFA-regulated muzzle device engineered to deliver measurable signature and recoil reduction on 300 Blackout platforms. Designed for rifles with 5/8x24 threads, it mounts flush with a 0.0 over-the-barrel requirement--installation is possible only when the barrel shoulder sits even with or ahead of any obstruction, ensuring a true direct-thread interface. Installs using included shims and torque tool--no adapters required. Maximum barrel diameter