I suppose the rules dictating what cartridge is acceptable for deer hunting are geared toward the "average" hunter/marksman and really don't reflect what is possible when an expert marksman/stalker is involved.Many novice and/or inexperienced hunters get overly excited and lose their rationale when confronted by a chance to score a trophy and take shots that they should not have taken.I would imagine a .25 or .30 caliber,or larger,would make up somewhat for less than ideal bullet placement in these situations,more penetration,more damage and a better blood trail.I believe,for the unexcitable and expert shot,that a .22 rimfire would be perfect under some conditions,for getting the game. I also believe that using a .22 even for the expert would greatly limit the chance to score simply because an "expert" is not going to take shots where wounding and losing the game is a possibility.That 10 point buck you just wounded and ran off to die in the neighbors woodlot has a good chance of being claimed by someone else in these days of trophy fever that seems rampant among those not steeped in the tradition and ethics of hunting.