We have a .177 Gamo Varmiter. With the gold Raptor pellets it has the power of .22. We kill squirrels with it all the time. When you hit them they drop like a rock. Personally I think we could easily kill a coyote with it. The Gamo is really awesome. Comes with scope, laser and flashlight.
I love my Gamo with 4x scope. Ten year old grandson shoots a 3 shot group at 35 yards you can cover with a dime. Paid $129 at Bass Pro Shop. Killed a racoon with it. Shoot nothing but ordinary lead pellets, .177 cal. Love it.