I currently have a 7.62x39 upper, and I am looking at something smaller.

Everyone has a 5.56, but I was looking at the 5.45. There are two "hunting" rounds, the Wolf 55 gr. soft point
https://www.youtube.com/watch?v=OhF91Nq0JYw

and the Hornady 60 gr. Vmax
https://www.youtube.com/watch?v=hAdpJE9Yi3s

As well as the 7n6 for anything else.
https://www.youtube.com/watch?v=-Oq3ZEZ7YFw

With the 55 gr. SP at $.25/rd shipped, and the V-max at $.36ish/rd shipped, the only concern is reliability.

For Central KY, is there a need for more accurate ammo, when shots will be <200 yards?