I have seen this question come up a few times, and I have some thoughts to add, with the preface that I have never taken a coyote, even though I have went out specifically to do so.
First, lets get the main point out of the way. When talking about airguns, do not focus on the airgun's caliber without knowing what the airgun can deliver in energy. One airgun may put out 100fpe while a different airgun may put out 50fpe
in the same caliber! When I hear you specifically say .257, I automatically think the shooter was using a Texan, which slings .257cal with a significant amount of energy.
I currently have two airguns:
- FX Maverick VP .30cal pushing a maximum of 95fpe.
- Benjamin Bulldog .357cal pushing a maximum of 205fpe.
The maximum distance you can take game depends on two factors:
- Your accuracy at that distance.
- How much energy does your shot have at that distance, which also depends on if you are taking:
- A brain shot.
- A body shot.
Let's say that we want to be able to land our shots within a 1.5" diameter, which should give you an adequate kill zone for both targets. At 100 yards my .30cal can put 70 fpe at the target, and my .357 can put out 170fpe on the target. Both of these energy levels are able to take a 40 pound yote (BTW, 40 pounds is a big yote) with a head shot, but you may have have a harder time with a body shot with the .30cal if you hit the shoulder.
In summary, taking a yote depends on a lot of factors. Only you can determine how much airgun you need and how far that airgun will work for you.