The only time a .22 lr is an ethical fox gun is at extremely close range or if the animal is in a trap. I have mainly had experience with grey fox whcih are harder to kill then a red fox. Last year I killed 4 greys when predator calling. All I had at the time that would not have completely obliterated the fox was either a .22 or a shotgun but I opted for the .22. In hind sight a shotgun would have been much better all but once. One of the fox I hit 7 times in the vitals before I had to put it down with a shot that connected with the spine at the bease of the skull. In the psat two years all but one fox has come in close enough for a shotgun with number 4 buck to have killed. Alll the ones shot with a 22 required multiple shots. To prove that grey fos are extremely tough I'll tell you a story about one I shot while deer hunting. I was shooting a 50 caliber muzzleloader with a 335 grain xtp mag pushed by 90 grains of powder. I had a grey fox come within 8 yards before I shot it. I saw it spin out and run off and I knew I had hit it. The bullet had punched a hole bigger then a softball in the middle of it's body but it still managed to go 45 yards without lungs and it's guts hanging out. So this year I went with a 204 ruger. It shoots laser flat past 300 yards and will knock a fox down everytime. As long as the shot are in the chest area there will usually be no exit hole and only a very small entrance. I've shot 11 fox and countless nutria (up to 20 pounds) and not a single animal has taken a step after being hit with this gun. The 204 is very fur friendly but not very friendly to the meat. A 204 is the perfect varmint/ predator gun and can humanely kill coyote sized animals.