The Bullet and the Deer

By Randy Wakeman


Sex does not affect the toughness of deer. Bullet shot placement has a far more profound influence on terminal effect than does bullet caliber or style.

Trauma to the spine anchors deer instantly; all other wounds allow some reaction. Deer shot well in the thoracic cavity will drop within 50 yards or less, on average. Fully 1-in-4 deer will give little or no sign of being shot and will travel roughly twice as far as (other) well hit deer. "Soft," expansive (deforming) bullets are more likely to drop a deer instantly given a hit proximal to the spine, but only slightly reduce distances for deer that run.

These are the conclusions based on the Charles Ruth of the South Carolina Department of Natural Resources game study. It dispels several myths and campfire tales perpetually used by delusional advertising departments. Within reasonable limits, there is no magic cartridge or brand of bullet and .22 centerfire cartridges are poor choices for even the smallest deer.

HYDRODYNAMIC HYDROSTATIC SHOCKERS

The notion of "hydrostatic shock" is silly. The sound speed of muscle tissue has been measured to be about 5150 fps and that of fatty tissue around 4920 fps. (Source: A Cavitation Model for Kinetic Energy Projectiles Penetrating Gelatin, Henry C. Dubin, BRL Memorandum Report No. 2423, US Army Ballistic Research Laboratories, December 1974). Even varmint bullets do not have an impact velocity this high, let alone an actual penetration velocity exceeding 4900 fps. Unless the bullet can penetrate faster than the inherent sound speed of the medium through which it is passing, you will not observe a shock wave. Shock cannot happen due to bullet impact, much less the junk-science terms like hydrodynamic or hydrostatic shock.

Although the old Dead Right There (DRT) hyperbole persists, unless it is a spine shot (which includes the high shoulder shot) there is no reason to expect the instant anchor or DRT. That would also include high risk (meaning small kill zone) shots like the neck and brain.

There have been some bizarre efforts to try to reinvent the hydrostatic shock idea: shooting dogs and pigs in their legs and looking for changes in brainwave activity, recounting tales of someone shot in a Kevlar vest, then later developing epilepsy, or the blasting of fish underwater that are stunned by the explosive charges. It has now been called "remote injury." No one in their right mind suggests that you shoot a game animal in the leg and wait for the hydrodynamic shock to kick in, perhaps except for Michael Courtney, PhD, who apparently thinks that a ballistic pressure wave is a significant factor in wounding ballistics.

It is small relevance to big game hunting where we are not blasting fish underwater, we do not seek to shoot animals in their legs, game animals don't wear Kevlar vests and we are not waiting for signs of epilepsy at a later date. The goal of ethical hunting is a very quick, clean kill and 100% game recovery, not struggling for later signs of brain injury or memory loss.

Sadly, this is what can happen when well-established medical terms like "shock" are carelessly thrown around. Shock is used in firearms as a marketing term, nothing more. It is bizarre to even use it with small arms, for shock is well-defined in the medical community. As in Cardiogenic shock (due to heart problems), Hypovolemic shock (caused by too little blood volume), Anaphylactic shock (caused by allergic reaction), Septic shock (due to infections), and Neurogenic shock (caused by damage to the nervous system).

While the aspiring marketing con-artist may struggle to characterize a high shoulder shot that anchors a deer due to spine damage from neurogenic shock into knock-down or hydrodynamic shock from some new wonder cartridge, it is offensively inaccurate. A spine shot is a spine shot, just like always.

It was the late Jack O'Connor who denounced the sloppy type of hunting that left more game in the field than was brought in. Flip side, it was Roy Weatherby that, in order to tout his magnums, intentionally gut-shot African plains game.

A whitetail deer hits 30 mph, or 44 fps, or 14.67 yards per second. In about three seconds, a properly double-lunged deer is quite dead, falling to the ground unconscious.

EXPANSION

Bullets that greatly deform offer only minimal benefit and increase the potential for spine damage. As Dr. Martin Fackler has shown again and again, expansion is a generally good thing, but never at the expense of adequate penetration.

SHOT PLACEMENT

Bullet placement is, overwhelmingly, the most important factor in quick kills. All the factors that enable excellent shot placement come into play. Manageable recoil, accuracy and short ranges all enable better shot placement. Therefore, the more lethal hunting rifle has recoil levels that do not negatively affect your shooting and is reasonably accurate. Shorter ranges invariably make any shooter and any firearm more lethal.

BALLISTIC COEFFICIENTS AND MUZZLE VELOCITY

The shorter the time of flight, the less the projectile can be affected by wind. To the extent that helps shot placement, bullets with high initial velocity and low levels of velocity erosion are the more lethal bullets, assuming equal bullet construction and terminal performance. It isn't because BC is a measurement of lethality, nor is it because a higher velocity alone kills game beyond dead.

A short time of flight means greater field accuracy and to the extent BC and velocity helps those components, they make a bullet more reliably effective, meaning more lethal.

BALLISTIC GELATIN BOGUS BINGO

It was Dr. Martin Fackler who largely popularized calibrated ballistic gelatin as a tissue simulant for comparison purposes. The good thing about it is that it is a consistent test medium. The bad thing about it is that it is a consistent test medium.

It has resulted in too many people gawking at and measuring a gelatin mix, somehow incorrectly assuming that it is actually analogous to living tissue with airway, breathing, circulation and bones. No living hide is present in blocks of gelatin, no bones to smash though, no skin, no fat, no muscle, no lungs. The penetration of a projectile into ballistic gelatin is not comparable to penetration in a big game animal. Double-lunging a game animal means, naturally, the bullet is going through a pair of gas-bags, a far easier task than going through muscle, much less bone.

To further complicate matters, living tissue is highly elastic. Although some are fixated on entrance and exit wound size, that has scant little to do with the volume of internal damage.

THE RESULT

Nothing bags a deer appreciably better or quicker than the old .45-70 Government, using a 405 grain bullet at 1405 fps, at typical whitetail hunting ranges of 86 yards average. Yet, the .45-70-405 load has a +/- 3 inch MPBR of 133 yards. At 150 yards, just a 10 mph crosswind means 5.85 inches of wind drift. At 200 yards, 10.24 inches of wind drift with a 10 mph crosswind. The limitation is not one of lethality, it is of difficulty in precise shot placement.

You still have to hit what you are shooting at, in the right place. The time of flight with the .45-70-405 shows its limitation: getting to 200 yards takes .518 seconds. In slightly less time, .507 seconds, the .270 Winchester makes it to 450 yards.

The dramatically lower wind drift of the .270 Winchester shows why it is easier to accurately place a shot. While the .45-70-405 has over 10 inches of 10 mph wind drift at 200 yards, the .270 Winchester has under 8 inches of wind drift at 380 yards. The .270 is not actually more lethal, but it becomes far more effective as a practical matter, due to its superiority in accurate shot placement at longer ranges.

Advancements have not been in actual lethality, only in effective range within the basic parameters of the same time of flight and equal or less wind drift. Neither the anatomy of a deer or other game animals has changed in millennia. Nor have the core attributes of a good shot: shot placement, adequate penetration and destruction of vital organs.




Back to Rifle Information

Copyright 2014 by Randy Wakeman. All rights reserved.


HOME / GUNS & SHOOTING / NAVAL, AVIATION & MILITARY / TRAVEL & FISHING / MOTORCYCLES & RIDING / ASTRONOMY & PHOTOGRAPHY / AUDIO