Scott47,
Accuracy is the key to any varmint rifle. Does it shoot consistantly with the loads you want to use. Lot's of work on the rifle range will tell you if the rifle is worth keeping. If it shoots to your satisfaction then the Winchester model 70 is the right one for what you want it to do. Just remember, the .223 is a medium range varmint cartridge. With a velocity of about 3100 fps for the 50 grain bullet you should be able to keep your groups around the 1" size, sighted in at 1" to 1 1/2" high at 100 yards. This should give you a point blank range out to about 250 yards with out any hold-over on a target the size of a coyote. An adult coyote will measure about 7 inches from the top of the shoulders to it's brisket. If you have to consistantly shoot at longer ranges then 250 yards then step up to the 22-250 or 220 swift or even the newer cartridges that have been developed in the last few years.
I hope this helps. Just remember, accuracy is the key for far fewer frustrating days hunting the very smart coyote.