I was just wondering if there is a round that can be be used for smaller game but also take down coyotes and groundhogs.
There is.
It's .223 Remington.
If a twelve gauge at ten feet isn't too much for rabbits a .223 won't be either.
I have several tournaments done and haven't blasted a bunny in two.
Once they are dead they are dead. The idea of "overkill or under-kill" is moot if the animal is dead.
I just don't see how
the premier varmint round is somehow "unethical" for varmint sized creatures.
As far as diameter, it's roughly the same size as a 22LR. Be a wiseguy to your friend and let them know it isn't "bigger".
I imagine it can be done, but coyotes with 22LR is going to be tough. And any game more medium than that it's only good for poaching.
Even the Hornet or K-Hornet lack quite a bit of energy compared to the Remington.
I don't buy into the too much gun. A 45/70 will leave a rabbit just fine for dinner, unless you end-to-end him on purpose.
As always, shot placment.
What kind of hunting are you doing?
Bench/blind, stalking, walkabout? Those play into your choice of cartridge too. Just as much as the Game you're hunting.