Wes/Tex said:
Yep...any ball or slug that completely penetrates takes a fair portion of it's kenetic energy with it. Ideally, you want everything left in the critter.
Just for another perspective, I think this is an area open for additional thought, or at least clarification. My personal view is limited to Eastern Whitetails, but will unashamedly say an awful lot of them now, taken with stout powder charges using several calibers & gauges of rifles and smoothbores... .40/.45/.50/.54/.58/.62cals for comparison.
Observations / conclusions:
1) I've had a lot of complete pass-throughs and while technically speaking some additional energy was indeed spent in the woods on the other side of the deer...that doesn't mean anything at all about energy being taken away from the energy already expended inside the deer;
2) A complete pass-through means the projectile was under a much stronger head of steam across / through the entire deer's body, across more vitals, creating much greater trauma / wound channel / damage than one which slowed down and came to a complete stop somewhere inside a deer's body;
3) Anyone who has taken enough big game knows that it is not uncommon for an internal organ to block blood loss out of a single entry point, but virtually never blocks blood loss from both entry & exit points from a complete pass-through...a huge benefit regarding the possible need for blood trailing.
4) I don't believe the notion that a ball stopping inside a game animal is the better choice simply because it can be claimed that "all the energy was left inside the animal".
Reality is that such a ball simply ran out of steam inside, had less energy to expend to begin with...yes, it certainly expended it all inside the animal...but that's because it slowed down and stopped.
5) One that stops bulging the hide on the far side is of course the best of all those that stop somewhere inside, but it’s impossible for us to manage a shot to do
that...in addition, the lost benefit of blood trailing would be a negative”¦when it could have been had if that ball had just a little extra umph (weight / velocity) to break on out through that hide.
At any rate, prior to my switching from heart shots to high shoulder / vertebrae shots to drop Whitetails in their tracks...my personal experience in all the calibers was to use a larger caliber ball with plenty of weight and the velocity to drive it so I'd get a pass-through on a Whitetail body shot for the reasons stated above.
Others mileage may vary...