John-
The .223 is a fun round to shoot with.  Less blast and longer barrel life then a 22-250, and it works fine on coyote.  I use an AR-15 for coyote, and it works great with 40 grain bullets.  They tend to blow up and stay in the dog, minimizing pelt damage.  If you don't reload, there is a big selection of ammo available, from frangable 40 grn to NATO AP and tracer ammo, and everything in between.  Enough reasons to buy a new gun, right?
PS- Check out the CZ bolt action in .223.  I just bought one in .204 Ruger, and it shoots just as good as my heavy barrel Remington 22-250's, but weighs about 3 1/2 pounds less, scoped.  It's the gun I use for coyote now in PA, where I cant use a semi-auto.  That little .204 bullet sure kills em quick, velocity does kill, at least up close..

Larry