I got a friend that built a short barreled , suppressed 300 blackout with an IR scope, kills a ton o pork with it, but he set with his set up, 100 yds & that's it.
Anything shot sub sonic isn't very useful over 100 yards.
I like the idea of a 30 Cal sub. The only reason I would get one is because it is in an ar platform. A 308 bolt shooting sub ammo with a can would be better for hunting in my opinion.