A 40 grain .22 mag at 100 yards develops "at least" 100 foot pound of energy ( more rather than less). For those that don't know - that's 100 foot pounds of energy per square inch. That means if you hit a 50 pound animal at 100 yards with a 40 grain .22 magnum, you will be hitting them with twice their body weight all in one square inch of where the bullet strikes. That's like a 100 pound boxer (prize fighter) being hit by a 200 pound boxer. How long do we think that 100 pound boxer will stay on its feet?