In a discussion of Non Spinal Column bullet wounds, I do think it matters a Lot what physiological state the animal is in (adrenalin, oxygen level, heart rate, blood pressure, etc.), as to how far it may travel after receiving a particular fatal hit that created a certain measurable degree of damage. An animal with a wound that does not immediately drop blood pressure to zero does retain willful action for a lesser period of time if it is calm when shot, as compared to an animal that is pumped full of adrenalin & oxygen, as long as there is not sufficient time to for the blood to carry a sudden release of adrenalin throughout the body from the effect of the bullet impact.
Adrenalin raises heart rate and oxygenation, and limits blood supply to extremities driving the available oxygenated blood to the central nervous system and organs. It is how it works.
It also matters how much damage is created in the organs in question by the bullet impact. Some wounds will close, and may eventually heal. Others incur damage to an extent that the body cannot stop blood loss sufficiently through clotting mechanisms to prevent a rapid loss of volume and drop in blood pressure, thus quickly starving the brain of oxygen.
Don't think that clotting is a scab. Clotting is a function of platelets in the blood, in response to some types of trauma, and can even occur inside of animal that does not have open bleeding and blood loss. Think of a clot as creation of a plug, and it’s a reasonable analogy. Those great big slippery brownish red blobs in a deer’s chest cavity when you gut it after a heart shot are clots. They are not busted up organs as some think. Organs have definitive structure, clots do not.
When the brain stops getting oxygenated, death occurs. If the brain keeps getting oxygen, the animal will stay alive. Perhaps "alive" is not pretty, and a wounded animal will develop infection or become immobilized, but if blood is pumping and oxygen is getting to the brain, the animal will be alive. This is setting aside discussion on starvation.
I started this off w/ "non spinal column". I don't think much of shooting game animals on the spine, generally. I have shot game this way, and the common proponent refrain is true: immediate cessation of motor control is achieved. The result is the '...rug was jerked out under him...' response.
However, the target area is small in relation to thoracic cavity shots on heart/lung, and the proper aiming point for spinal shots can be misleading. The proper aiming point on the neck, in relation to vertical span, is different at the chest cavity end than at the head, it is also at a different point on the span of the neck for a heavily muscled buck, or one in the rut, than a doe. I have also seen misplaced shots let deer survive with what amounted to a tracheotomy. I remember a buck shot this way by a relative return to the bait pile the next year and it blew steam out of a hole in its neck.
A non fatal shot here is not necessarily a 'clean miss' like so many would believe. These non misses can easily become infected and lead to a lingering death.
Most sporting cartridges, sold for a given purpose such as deer hunting, while employing a properly designed bullet for the purpose, will create sufficient damage to rupture a heart, or create a wound through the thoracic cavity sufficient to cause collapsing of the lungs, resulting in reasonably quick death for the animal.
Note "sold for a given purpose, while employing a properly designed bullet".
To the people who want easy energy number comparisons to defend why one cartridge is OK for use on a game animal because something of similar energy worked, keep in mind that a 25 gr 17 caliber frangible bullet has Exactly the same kinetic energy at 4000 fps (realm of 17 Remington) as a 400 gr 475 cal hard cast homogenous lead bullet traveling at 1000 fps (480 Ruger realm of operation).
Kinetic energy = 1/2MV^2. 16 times the Mass, at 1/4 the speed = same energy.
No one should think for one second that this type of 17 caliber bullet will penetrate as well, or cause the same type of wound cavity as the 475. If you disagree, you have never looked at ballistic media tests, nor done thorough post-mortem examinations of game animals.
Fatal is fatal however, and if a shot sufficiently disrupts the organs that infuse blood with oxygen, or pump the oxygenated blood to the brain, then the animal so shot will die relatively quickly and it won’t matter the brand of rifle that fired the cartridge or caliber bullet that struck it.
I have shot a good number deer using pistols (44 Rem Mag, 475s, 30-06, 35 Remington) and rifles (7x57, 30-06, 8x57, 35 Whelen Imp, 416 Wildcat off 30-40 Krag, 44 Rem Mag), as well as a good number of antelope (using 6x250 Imp, 6-280 Imp, 7mm RUM, 30-06), boar (35 Whelen Imp), bison (35 Whelen Imp & 500 Linebaugh Long), under varying conditions regarding impact point, yardage to target, bullet construction, etc.
I can tell you from experience and an understanding of anatomical function that if the heart is ruptured, i.e. cardiac muscle tissue is torn to significant extent by hydraulic action of bullet impact acting on the blood volume inside the heart, or the thoracic cavity is penetrated and a hole through both sides is created large enough so that it cannot seal, thus causing rapid collapsing of both lungs, there will be no noticeable difference what firearm you used given that the animal is in a similar state as another of its species before being so shot.
Here is where the rub comes in: most people want to debate '...what works best...' over a range of cartridge/bullet availability that were all designed to do basically the same thing. Most medium game shot in the US are whitetail deer. Most hunting centerfire medium game rifles and cartridges sold in the US commercially are designed to kill whitetail deer.
All the cartridge/bullet combinations designed to reliably kill whitetail deer will kill whitetail deer if employed correctly. So, if you look at "dead deer" as the criteria, then this very gross metric makes a lot of things equal. If I have rained on your '...mine is better...' parade, then sorry, but facts are facts.
The deer / antelope / boar I have shot with different cartridges and bullets all acted the same if the internal damage was the same. Ruptured heart, deer go flop, if calm. Immediate collapse of both lungs, deer run 40-60 yards if calm. How far they move after the shot is extended if they are ‘jacked up’.
If you look into the detail of How the cartridge/bullet killed the animal, and how forgiving the cartridge/bullet combination is for shot placement (can it handle impact of leg bone during entry into the chest cavity, can it penetrate far enough to make it through rear haunches on a facing away presentation, etc.), then you must make a different evaluation and "Does it work" becomes more refined.
In field hunting conditions things happen: some intervening object deflects the bullet in path, a hunter chose a bullet fine for 300 yd impact because they hunted crop fields and then actually shot the game out of a hedgerow at 50 ft causing over expansion & shallow wounding, buttstock slipped on a shoulder in an awkward shooting position, etc.
Sooner or later, if a person hunts enough, a shot will be taken that results in poor bullet placement on the animal. We don’t hunt with benchrest unlimited guns for animals with kill zones painted on their sides, presented perfectly aligned to the hunter and bullet path. For this reason I prefer to use a cartridge & bullet that are as forgiving as reasonably possible for the game being hunted, no matter how it presents, and this does not have to be a belted magnum nor a 40+ caliber cartridge for deer. Bullet selection, given sufficient cartridge choice is a key component.
For these same reasons, eventually a hunter will need to take more than one shot on a game animal to kill it. No shame in that, at least as long as it is an occasional occurrence due to uncontrollable factors.
Though outside of this thread, but seemingly repeated often in this type of discussion, extrapolating what works for controlled conditions of killing domestic hogs or beef cattle for slaughter, what works for a poacher who is primarily concerned w/ detection of an illegal act rather than wounding game, or some anecdotal success in an emergency situation with a 22 RF and a grizzly bear, is not really relevant to a discussion on ethical hunting practices.