do what every fox trapper in the country does and put the guns away........ lightly "tap" the fox on the nose and stun him and then take one foot and pin his neck down and the other heel and hit your heel into his heart as he lays on his side three or four times or just do what I used to do and put your foot on his neck and pound with your clenched fist on his heart and feel the heart pound and then reach up into the rig cage through the skin and pinch his heart and squeeze. Easy to find because it is beating very fast.
there is no need to mess with blood, guns, sewing up holes. for bobcats and coyotes i use a .22 short in the ear. simple