.243 will open a fox like a granade if you hit any bone, they are very thin skinned. Birddog had good suggestions, I like the .22 mag. Shotgun with #4 or #6 shot will work to about 40 yrds.
Real Estate-Exclusive Buyer's Agent MD Eastern Shore
Jake
For us the shotgun has out performed the rifle 2 to1. Except for the ocasional red, if they are truly interested they will close the distance to within 40 yds in a hurry. For a rifle you need to be able to get on the target and shoot quick they do not stand still for long. A grey will be on top of you in no time and will often sneek in from the side. Most the rifles we have used have been light, .22 .22 mag, .17, .223. others are a little loud and draw attention from neighbors and you will be vistited by the law. not that you are doing anything wrong, but most think it is poachers spotlighting deer.
Don't get crazy with the electronic call. Start real low. Get a mouse squeaker hand held, like a dog toy. Always scan a field first with the light before calling. Start with the mouse squeaker and scan with the light for a few minutes before starting with the electronic caller.
On dark nights we use red lens cover on light and during a full moon just the white light. Hold the light high with the direct beam well above the field, you will be suprised they will "light up" with minimal light. When they get close and you are ready for a shot bring the light down and "burn" them. They will typically stop giving you the best shot. We have found that a low power scope on the shotgun works best. Red dot scopes have not worked well for us, it is hard to pick up the target with the red glow.
The most succesful hunts have been on snow covered nights with a full moon. Don't use a light unless you have to on these nights. You will be able to see without one. Add a light ice crust and they will come from everywhere. Guess they can't mouse through the ice so they are a bit hungry. Can't wait to see your pics.
Oh, don't forget the most important thing to consider is wind direction. You think a deer is bad. Try and set up in a way that the fox can not flank down wind. Reds especially will try to get downwind before they come in.