See our ammunition write up on Tactical Gun Review:
http://tacticalgunreview.com/dallas-reloads-300-blackout-subsonic-ammo-review/
210 Sierra Matchking loaded subsonic @ 1040 FPS. Brass is NEW Norma 300 Black Out head stamped brass. Powder is either Hodgdon or Alliant powder, depending on which bullet is loaded. Primed with CCI #400 small rifle primer. Standard 1:8″ twist or faster (1:7″ twist) will stabilize this bullet. 100 rounds per order.
Subsonic, 100 rounds per order.