Some of what it can be used for would include coyotes, woodchucks, bobcats, crows, and turkey with the right bullets.
243 is too much for squirrels and rabbits - if you want anything left to eat.

The 243Win. is a great varmint cartridge, but should be considered a MINIMAL deer
cartridge. Use premium ammo only for deer hunting (ex.: nosler partition bullets).
Broadside heart/lung shots should be the rule, and try to keep the range to within
200yds. for deer.