I use a .223 and have killed several with no problem!
One was a head shot a 220 yards!
I reload 55gr V-max.
Unless you are just looking for a reason to purchase another rifle, which is fine, any centerfire rifle will kill them dead!!
Depending on where you are at and whether or not you plan on saving the fur, you may keep your selection the .223 or 22-250.
Other wise, I have never seen a coyote too dead!! :biggrin: