Ive always used #4 buck in a shotgun when hunting for coyotes ive never taken a shot out to 40 yards but in know a25-30 yard shot youll put about five pellets into the kill zone (head)with a few others all around with a 2 3/4" shell. if you use a 3" or 3 1/2" the results would be devesitatingly effective. if your worried about sewing holes dont worry too much #4 buck is only.24 caliber.body shots would be kinda messy at close range though.