6.5 Grendel for supersonic shooting. It stays stable/supersonic for further. The higher BC's of the 6.5 bullets realise flatter trajectories than the 30cals. This helps hitting the target when judging distance.
Either 30-30 or Blackout for subsonic shooting. You might find it easier to load with the lesser case capacity of the Blackout. Obviously you'll have to consider the twist rate for heavier bullets. The bolt action of the 788 will permit the quietest and potentially most accurate suppressed subsonic however the Blackout has the utility of semi-auto in an AR platform. Subsonic hunting is a niche sport - not many people do it. It requires the handicapping of your calibre. It is also akin to bow-hunting with a rifle.
Either 30-30 or Blackout for subsonic shooting. You might find it easier to load with the lesser case capacity of the Blackout. Obviously you'll have to consider the twist rate for heavier bullets. The bolt action of the 788 will permit the quietest and potentially most accurate suppressed subsonic however the Blackout has the utility of semi-auto in an AR platform. Subsonic hunting is a niche sport - not many people do it. It requires the handicapping of your calibre. It is also akin to bow-hunting with a rifle.