If it was 300BLK suppressed, there would have been a ton of bullet drop at 140 yards assuming they used subsonic ammo. It would have likely been a much less flat angle than the bullet blur the photographer snapped.

EDIT: Ballpark figures for 5.56 supersonic ammo and 16” barrel at 150 yards is 3.5” of bullet drop. The same distance with 300BLK subs is 36”. That is 10x the drop.

If it was 300BLK suppressed, there would have been a ton of bullet drop at 140 yards assuming they used subsonic ammo. It would have likely been a much less flat angle than the bullet blur the photographer snapped.