I succesfully hunt coyotes with a mini 14, 581 series but I get them to come within 100yds.
How long of a range are you expecting?
You may want to get a bolt action in 22-250 or something along those lines or maybe 243 if you are thinking long range varmiting.
While the mini is my favorite rifle, I don't consider it a long range rifle.
Others may be able to attest to its longer range capabilities but at my ranges it's perfect.
I'd say try it out first before adding anything to it.