We are small family run business based out of Taranaki, New Zealand, who specialise in cartridge research and a number of various hunting related services. We survive off the generous donations of our website users and the income we derive from online advertising and our other services. Please click here to find out more about us.
If you find the resources on this site to be valuable, we would be sincerely grateful if you would help us to continue our research by advertising your products on our site. Please click here for more details.
Readers can make a donation by clicking here. Donations are extremely helpful when we are answering lengthy, technical, trouble shooting emails. If we have helped you resolve questions via email, a small donation would be grateful.
Part 1 Game Killing
Effective game killing
HistoryAlthough ballistics studies may appear to be a relatively new field of research, it is as old as man himself. One of the first technological breakthroughs in arms was the invention of the bow and arrow.
Early bow hunters took effective game killing very seriously. The method in which the arrow killed was through its blades, which were as broad as practical, severing as many arteries in the animal’s chest as possible to cause death through blood loss.
On average, the primitive bows of the world had a draw weight of 40lb which as power goes, is very light. The bow was of course, also highly valued in warfare. Warfare drove bowyers of the day to develop ever more powerful bows to meet battlefield needs. As soldiers adopted heavier armor and greater formations, the power of the bow increased from 40 to 80lb, from 80 lb to between 120 and 150lb and in extreme cases, up to 200lb. By the middle ages, two distinct types of arrow were in use, a very heavy armor piecing arrow and a much lighter flight arrow for long range volley fire.
As the bow became a more effective battle weapon, it also became a much more effective game killing weapon. European hunters discovered that rather than try to fire and lodge an arrow into the chest of an animal, an 80lb hunting bow firing an arrow of sufficient weight to create a complete pass through, effected a much quicker death. The combination of both an open entry and exit wound prevented the chest cavity of shot game from developing a vacuum and created a fast bleed. The faster bleeding caused a much faster kill and this in turn enabled the hunter to locate downed game from within a short distance of the initial shot rather than the common risk of being unable to locate the dead animal whatsoever. The complete pass through of the arrow also created a swarthy blood trail to follow. It is from this historical experience that modern European hunters prefer rifle ammunition that completely penetrates and exits game.
Dual holes as a means to drain a vessel is a most basic principle of physics. Today, this principle is employed in the design of all fuel systems and can be duplicated by trying to empty the liquid contents of a tin or drum, first with one hole, then with an opposing breather hole.
The black powder musket eventually superseded the longbow however; it differed very little in its method of killing. The musket produced the most effective kills when loaded with the widest possible ball. A later invention was rifling to impart a spin on the projectile for greater flight stability. Rifling not only added accuracy to the ball but allowed for the development of cylindrical shaped round nosed bullets. Eventually, cartridge design reached a stage where compromises had to be made. For instance, as much as .52 to .58” caliber bores were effective killers, they did not have the flat trajectories of the aerodynamic .38” bores. To duplicate the trajectory of a .38 bore using a .52 or .58 bore, the rifleman would have to adopt an extremely long, heavy projectile in his .52 or .58 caliber rifle and suffer the recoil. The black powder rifle reached the epitome of design with the breech loading .44 and .45 caliber rifles of the early to mid 1800’s. These bore sizes achieved the ultimate balance of killing power versus trajectory versus obtainable velocity.
After the advent of smokeless powder in 1886, much higher velocities were achievable causing bullet diameter and weight to be reduced in order to minimize recoil. The first smokeless cartridge projectiles featured round nosed bullets with a gilding metal jacket to minimize the fouling that would otherwise occur if traditional lead projectiles were fired at high velocity.
Regardless of the stability imparted to projectiles from rifling, round nosed bullets still showed slight irregularities in flight, the technical term called yaw. On impact, the yaw of the bullet increased, sometimes creating wound channels out of proportion to the caliber used. This phenomenon, described at the time as ‘explosive’, was first recorded by French researchers in 1848.
The next major step forwards was the introduction of pointed bullets to increase aerodynamics. These first appeared towards the turn of the 19th century. Prior to the development of rifling it would have been impossible to propel the pointed bullet point first as physics dictated that the centre of gravity being at the base would force the bullet to turn in flight and continue to fly base first like a tear drop. Rifling however, created stability to the projectile allowing only the slightest amount of yaw. Nevertheless, on impact, the pointed FMJ projectile had a tendency to tumble violently (not to be confused with the modern boat tail military bullet) and create a devastating wound.
By taking these discoveries to the extremes, it was discovered that a projectile with an exceptionally light but long point would maximize instability on impact. The English were perhaps the first to adopt a design based on this premise, filling the nose section of the military .303 projectile with cardboard or aluminum. The British military utilized this projectile until the design was banned by the Geneva Convention some years later.
After the pointed bullet, the next advance in projectile design came from the development of the tapered tail bullet now known as the boat tail. Designed to increase accuracy at extended ranges for military use, the boat tail moved the centre of gravity towards the centre of the projectile. This design, while causing slightly less yaw inside the target, successfully stabilized the projectile in flight at ranges of between 1000 and 2000 yards as the projectile passed from super to subsonic velocities, a transition that causes excessive yaw in flat based pointed bullets.
The sporting cartridge benefited greatly from military developments however, a departure in design occurred due to the fact that military convention dictated that full metal jacket bullets must be used in war to minimize excessive cruelty to soldiers as well as easing the work of the surgeon. Sporting projectile design differed after the discovery that an exposed soft lead nose or hollow nose caused expansion of the projectile on game and maximized wound channels. A major benefit of the expanding bullet was that after developing its frontal area, the weight and centre of gravity of the projectile were well forwards. The forwards weight created stability that lead to straight, deep penetration. This forwards transition of weight after expansion of an ‘ideal’ projectile is referred to as shoulder stabilization. It is worth noting that although expanding point projectiles have less penetrative abilities than FMJ round nosed dangerous game hunting bullets, expanded shoulder stabilized projectiles are far less prone to tumbling during penetration.
How bullets kill
A projectile kills by causing either one or a combination of the following:
1. Blood loss
2. damage to the nervous system
3. destruction of vital tissue and organs
4. blood poisoning or asphyxiation
Each causing the effect that life can no longer be sustained.
For hunting purposes, the primary task of the projectile is to provide a fast humane kill. This minimizes suffering to the animal and simplifies location of the carcass. Destruction of the major nervous centers such as the brain or forwards portion of the spine cause the fastest killing but such targets are often difficult to hit.
The most reliable method of killing is through causing blood loss. Blood loss is categorized as either fast bleeding or slow bleeding. Fast bleeding refers to the destruction of the major arteries of the chest and neck creating a fast kill while slow bleeding refers to the muscles and arteries that feed them, such as the femoral artery. When slow bleeding areas are destroyed, the result is a slow kill.
When a projectile destroys vital organs such as the lungs, liver or heart, death occurs in the first instance through blood loss, not through the destruction of the organ itself. This is simply because these organs are major carriers of blood therefore kills are relatively fast.
Slow kills can also be caused by asphyxiation as a result of minor wounding to the lungs or neck while gut shots cause a slow death through blood poisoning by the introduction of digestive acids into the bloodstream .
The modern high power sporting cartridge relies on high velocity loaded with soft expanding type projectiles. As the projectile strikes flesh, it mushrooms (or tumbles) causing displacement of tissue through both physical contact as well as pressure. The projectile transfers its kinetic energy to the surrounding tissue causing acceleration of fluid particles in and around its path. This creates an explosive temporary wound channel that subsides to a wound channel far greater than the diameter of the projectile. The temporary wound channel reaches its maximum size within one millisecond, collapsing to its final size within several milliseconds. The size of the temporary wound channel is proportional to how much energy is delivered and can be given numerical values. In both military and sporting applications these two types of wound damage are referred to as the temporary wound channel and permanent wound channel, both having the effect of causing blood loss, organ and nerve damage relative to shot placement.
Fast killingFast killing is an important factor for two reasons. The first is with regards to humane killing. Compassion must always be at the fore front of the hunters mind, at least in my opinion. The second factor of importance is the ability to secure game quickly, without losing the animal. In bush hunting situations, it is not uncommon for a dead run animal to be lost after travelling between 100 and 300 yards before expiring, falling into a gut or hole, never to be seen again. Frustrating, isn’t it? For the tops hunter, it means securing an animal on the ledge it was perched on. Dead running game on the tops can very easily expire when traversing a ravine, the animal falling, becoming stuck in a position that is neither recoverable from the top or bottom of the bluff system. Been there, done that, don’t want to go through it again.
In order to get the best results, it is important to understand the mechanisms of killing and how a fast kill occurs.
A common misconception when witnessing game collapse at the moment the bullet impacts, is that the force of the projectile has physically knocked the animal to the ground. We tend to call this an instant kill. Newton’s law suggests that for every force there is an equal and opposite force. To this end, the force of the bullet impacting game is no greater than the recoil of the rifle. So what causes the instant collapse or poleaxe as it is often caused?
Instant collapse occurs when the central nervous system (CNS) is damaged or electrically disrupted as a result of one of two mechanisms, either direct or indirect contact.
With direct contact, a bullet directly striking and destroying one of the major nerve centers, including the thoracic and cervical vertebrae, the brain or the autonomous plexus, regardless of velocity, will result in instant death.
Indirect contact refers to the effects of a high velocity bullet imparting its energy, creating a hydrostatic shock wave. In terminal ballistics, the terms hydraulic shock and hydrostatic shock both refer to kinetic energy transferred as shock waves through flesh however, each term describes different results. Hydraulic shock is a civil engineers term also known as water hammer but in terminal ballistics context refers to the pressure of accelerated fluid particles that create the temporary wound channel. Hydrostatic shock transfer refers to the effect when shock waves travel through flesh to distant nerve centers, disrupting their ability to emit electrical impulses.
The reason why game animals drop instantly with chest shots that do not directly strike the CNS, is due to hydrostatic shock transfer to the spine and brain. A high velocity cartridge well matched to game body weights imparts over half its energy within the first 2cm of penetration, creating a shock wave. This shock wave travels outwards via the rib cage until it reaches the spine where it disrupts the electrical impulses of the CNS. The result to the animal is an immediate loss of consciousness.
Along with the loss of consciousness, the projectile has also created a large wound channel, draining all of the body’s blood within several seconds. The loss of blood and damage to vital organs cause death to the animal before it has the chance to regain consciousness. This action creates the illusion to the hunter, that the projectile has knocked its victim to the ground, killing it instantly. More careful examination shows that the shot caused coma, followed by blood loss, followed by death. The hydrostatic shock created by a hunting bullet is identical in action to when a boxer is struck on the jaw by his opponent, disrupting the functions of the brain with a resulting loss of consciousness.
Hornady testing has revealed that a large wound cavity can cause a blood pressure spike to the brain, inducing immediate coma, though this is relative to hydraulic shock, not hydrostatic shock as described here. This phenomena also helps produce ethical killing.
Four major factors affect whether hydrostatic shock transfer occur and all are relative to each other.
1. Velocity. This has the greatest effect on hydrostatic shock. Put simply, the higher the impact velocity, the greater the shock. Velocity is also the most influencing factor in hydraulic shock, having a huge bearing on the size of the internal wound channel. Hydrostatic shock, in bore sizes from .243” up to .338”, begin to lesson at impact velocities below 2600fps and most modern high velocity sporting cartridges including the magnums gradually lose shocking power beyond 300 to 350 yards. Of the thousands of animals harvested during TBR tests, 2600fps has been the most common cut off point with repeatable results (reactions) occurring when deliberately testing the impact velocity of 2650fps versus the impact velocity of 2550fps.
A noticeable change occurs as bullet diameter is increased to .358” (such as the .35 Whelen) and larger bores. With the medium and large bores, hydrostatic shock can occur on our NZ game species at velocities as low as 2200fps.
Frangible bullets tend to produce coma at much lower velocities than traditional hunting bullets. With frangible bullets at low velocities, instant coma is due to hydraulic shock causing blood pressure spikes in the brain as discovered by Hornady ballisticians. These results can easily be seen in the field. In other instances, coma follows shortly after impact, most likely due to multiple pain centers being disrupted to such an extent that the animal must go into coma.
When testing hydrostatic shock on Bovines, it was discovered that impact velocities of 2600fps with suitable bullet weights (and construction) produced instant poleaxe in a repeatable manner. However, in many instances, Bovines would attempt to rise but that the action of attempting to rise resulted in increased blood loss with death following within seconds.
2. Bullet weight versus game weights. Where the bullet is too light for the intended game it may simply lack enough kinetic energy to cause hydrostatic shock, meeting far too much resistance on impact. This is a common occurrence with the .22 centrefires but can also occur in any cartridge, especially the large magnums when using light, very soft projectiles. A good example of this can be found in the 7mm Remington magnum loaded with various 140 grain fast expanding bullets. Although internal wounding may be sufficient, without hydrostatic shock, game break into a dead run.
Less obvious, is the result of using a bullet weight that is too heavy for the intended game. If the projectile contains too much momentum, the bullet may fail to meet enough resistance to impart energy where it is required i.e. the ribs through to the spine. Wound channels may be as wide as a lighter bullet however; the hunter may find that game run a long way before succumbing to the shot. These factors can create many difficulties for the hunter when selecting an appropriate load as a certain level of momentum is required if the bullet is expected to penetrate into vitals from any angle or give satisfactory performance on a variety of game.
A good example of a projectile that can cleave to its momentum is the Barnes homogenous copper bullet. Looking at the .308 Winchester, the 150 grain TSX, while being a very effective projectile for large bodied deer, can cause slow kills on light bodied deer at ranges beyond 75 yards (impact velocity of 2600fps and below). Internal wounding may well be very thorough, yet game still run considerable distances. In contrast, the lighter 130 grain TSX (along with the 130 grain GS Custom bullets) not only utilize higher impact velocities, but also meet greater resistance on impact, initiating more traumatic wounding.
3. Projectile construction. The third factor that effects hydrostatic shock transfer and counteracts bullet weight while also having the capacity to counteract impact velocity is bullet construction. For example, the stout Sierra .30 calibre 180 grain Prohunter, whether driven from the .308 Winchester or .300 Win Mag creates a large internal wound on goat fallow and Sika, yet it can retain too much momentum to initiate hydrostatic shock on these animals and kills can be very slow. The same can be said of some of the stout core bonded designs such as the 180 grain InterBond along with the Barnes TXS bullets. By simply changing to the 180 grain Speer BTSP or 178 grain A-Max, a faster kill can be obtained. These two projectiles are soft and highly frangible. The Hornady A-Max in particular can produce hydrostatic shock at impact velocities of 2000fps or lower where the ProHunter shows a clear cut off point at an impact velocity of 2550fps.
In contrast, as game body weights reach 90kg and above, the 180 grain Prohunter and its GameKing sibling along with the InterBond and TSX bullets, all come into their own, meeting a great deal of resistance on impact. Hydrostatic shock is still absent at impact velocities of 2600fps and below, but the heavy resistance initiates immense trauma and broader internal wounding than on lighter game body weights, resulting in a kill that is delayed by only a few seconds, as opposed to up to 45 seconds.
4. The fourth factor is bullet diameter and put simply, the wider the caliber, the less need there is for high velocity to initiate shock. Bullet weight can be higher as the wider frontal area meets more resistance at the target dumping energy more readily. Wide caliber bullets do however differ in performance depending on bullet construction. A stout .458 caliber bullet for instance can kill just as slowly as a stout .30 caliber.
The speed of incapacitation or killing is one method for which the hunter is able to measure a cartridges effectiveness on game in comparison to other cartridges. It must be remembered however that the word effective by definition in this instance describes the ability of the cartridge to achieve fast incapacitation through shock transfer and therefore has no maximum limit to power. An efficient cartridge on the other hand describes the ability of the cartridge to kill using the minimum necessary power.
At lower velocities, in the absence of hydrostatic shock, the most effective way to obtain fast killing is via wide internal wounding. The wider the wound, the faster the kill. Wide internal wounding also negates the necessity to use exacting shot placement. A good example of this can be found in the .243 Winchester. At ranges beyond 200 yards and especially at ranges of around 300 yards, the .243 can produce slow kills with rear lung shots due to narrow wounding. By bringing shot placement forwards to the line of the foreleg or 1 to 2” further forwards of the line of the foreleg, a fast kill can be obtained via direct destruction of the autonomous plexus (nerve ganglia between the heart and lungs). If however, such shot placement cannot be guaranteed, a change to (for example) the .270 Winchester, will ensure greater internal wounding with rear lung shots, effecting a faster kill.
Exit wounding also helps ensure faster killing by eliminating vacuums within the chest cavity which prevent blood loss. Sticking with our .270 example, the 150 grain Hornady Interlock or SST driven at 2900-2950fps tends to be more traumatic on deer at 300 yards than the 130 grain Interlock or SST driven at 3100fps because of the higher sectional densities of the 150 grain bullets which are more capable of rendering exit wounds.
Shot placement, as just described with the .243, can of course negate the need for hydrostatic shock or immensely wide wounding. An accurate but low velocity rifle/ cartridge combination capable of striking the autonomous plexus of game in a reliable manner will anchor game just as quickly as a cartridge capable of producing hydrostatic shock with rear lung shots. On the other hand, the hunter is not always presented with the perfect shot. Therefore, the more effective a cartridge is regarding both wounding and hydrostatic shock generation, the more forgiving it can be with less than ideal shot placement.
So far we have discussed Hydrostatic shock in great detail while only touching on hydraulic shock. Like Hydrostatic shock, hydraulic shock is increased at high velocities and has similar cut of points at different velocity parameters. Looking at one projectile as an example, the 130 grain .270 Winchester InterBond expands to a diameter of between 13 and 17mm at high impact velocities. The wound channel this creates through vitals is around 50 to 80mm in diameter. This is what I call disproportionate to calibre wounding and it is very effective. As velocity falls to 2600fps, wounding tapers off slightly, the internal wounds being around 25-40mm” in diameter.
As velocity falls below 2400fps, wounding gradually becomes proportionate to calibre, noticeably so at 2200fps. Between 2200fps and 2000fps (450 to 575 yards), the InterBond projectile expands to a diameter of around 8 to 9mm, creating a wound channel of around 8 to 9mm, resulting in slow bleeding and therefore, if the CNS is not destroyed, a very slow kill.
To regain disproportionate to calibre wounding at low velocities, the projectile must be capable of shedding a large amount of its bullet weight, up to 90%, allowing a cluster of fragments to create wide internal wounding to increase the speed of blood loss for fast killing. However, this does not mean to say that a .22-250 loaded with a varmint bullet will produce clean kills with chest shots on medium game, the cluster must also be matched to game body weights, having optimal density and momentum.
Although a frangible bullet is able to produce wide wounding due to mechanical destruction alone, hydraulic shock also occurs at much lower impact velocities than a controlled expanding bullet. As suggested earlier, Hornady research suggests that blood pressure spikes in the brain cause coma, resulting in (as much as possible) a painless death. Whether from a hydraulic or mechanical perspective, wounding of fragmentary bullets is much higher than that of controlled expanding bullets at low impact velocities, providing the cluster has sufficient density and momentum relative to game body weights.
During TBR testing, a packet of vintage Winchester Western .30-30 160 grain hollow point ammunition was tested on medium game animals. This is perhaps the earliest example of a frangible bullet. As best as could be determined after extensive research, it could be concluded that historically, the .30-30 was possibly not standing up to its design premise and that a frangible bullet was adopted to increase wounding capacity.
The .30-30 160 grain soft point load was intended to produce wide wounding and fast kills as a result of the newly discovered powders which generated exceptionally high velocities (for 1894). This was a complete turn around from past terminal ballistics research which had proven that the bigger the bore, the wider the wound. The .30-30 (.30 WCF) loaded with a controlled expanding bullet is not a great deal more emphatic than the .45/70, the .45/70 having already proven to be an emphatic killer. Western’s hollow point load was introduced a little while after the soft point. While the frangible .30-30 bullet would have been acceptable for use on the smaller deer species of the U.S, one has to wonder how this load faired on the Grizzly bear featured on the ammunition box of the .30-30 hollow point ammunition. The results would most likely have been disastrous. About 200 grains is a safe minimum frangible bullet weight for these body weights.
Frangible bullets are important at low velocities, especially at long ranges. A frangible bullet capable of rendering a wide wound in the absence of disproportionate to caliber wounding (high velocity) helps ensure fast bleeding for fast killing.
In conclusion, with ideal shot placement and utilizing a cartridge with sufficient power to penetrate the vitals of intended game, we can destroy the CNS and cause an instant kill- however this is often idealistic and unrealistic. With less than ideal shot placement, high velocity can initiate hydrostatic shock and hydraulic wounding to help ensure fast kills out to ordinary hunting ranges (300 yards). In the absence of high velocity, a fragmentary projectile can ensure fast killing via hydraulic shock and wide (mechanical) wounding, producing fast bleeding. In all instances, bullet weight and bullet construction need to be matched to the job at hand.
Two ways of looking at the projectile weight and construction equation are - light and stout versus heavy and soft. A light but stout projectile can deliver hydrostatic shock while having the tough bullet construction needed to deliver sufficient penetration. However, this has a range limitation, usually of around 300 yards, after which, careful shot placement is required. This can be counter productive in cross winds. Nevertheless, this method is often the most effective for minimizing meat damage on lighter medium game at ordinary hunting ranges (out to 300 yards).
When chest shooting heavy game, a controlled expanding projectile of a suitable weight and construction driven as fast as the shooter can manage, produces the fastest possible killing. As O'Rourke said, use enough gun.
A heavy yet frangible projectile may not deliver hydrostatic shock very far depending on game body weights, but providing the cluster is dense enough, it will be capable of rendering deep, broad and highly traumatic wounding across a wide range of body weights. Extremely soft and frangible projectiles can deliver hydraulic shock for neural trauma (blood pressure spikes to brain) at impact velocities of 2000fps. In Layman’s terms, a range of around 300 yards in the .308 Winchester and around 600 yards for the 7mm and .300 magnums. Frangible bullets can continue to produce hydraulic shock and basic mechanical wounding down to impact velocities of 1400fps.
Semi frangible bullets such as the Hornady SST can be used in multi task applications. A good example of this is the 7mm 162 grain SST which is effective on Red/Mule deer at close ranges (adequate penetration) yet is capable of producing wide wounding at extended ranges (around 1000 yards in the 7mm Remington Magnum).
There are of course finer variables which effect results. I have been continuously researching wounding for most of my life and the results and variables are far greater than can be covered in one short document. Nevertheless, a rudimentary understanding of the fundamentals of game killing, wounding and speed of killing can serve as a useful platform for a successful hunting career.
Meplat shape and surface area versus killing performance
The word meplat is a term used in ballistics terminology that has survived from a bygone era. The word itself is a french noun which means 'the flat of' and in ballistics it refers to the tip of a projectile. Meplat is not an adjective, it does not describe the shape of the tip or diameter in any way. Our current term could easily have been 'tip' or 'point' or even 'Fred' but instead, ballistic engineers of the world use the word meplat. The French were very much at the cutting edge of ballistics during the 19th century and the word meplat has survived out of an unconcious respect for these early pioneers. The term mostly likely stems from the days when all conical projectiles had flat points. The front was therefore called the flat and the rear dubbed the heel. Nevertheless, do not be confused, the word meplat simply means 'tip' in todays terms.
As most will guess, the shape of the meplat (tip) has a great effect on external ballistics (how the projectile flies through the air). The shape can also have an effect on terminal ballistics and performance with regard to projectile energy transfer on game, projectile expansion and stress to the projectile during this rapid change in medium. Put simply, a wide flat meplat projectile has far greater potential to transfer its energy immedietly upon impact than a sleek pointed projectile when bullet construction of both designs is equal.
The differences become even more pronounced when using solid, non expanding bullets, whether they be constructed of hard cast lead or full metal (copper) jackets. Unfortunately, a wide flat pointed meplat can also handicapp a projectiles potential trajectory as well as a huge loss in velocity and energy at moderate to longer ranges which can inturn result in low energy transfer.
Ideally, to fully utilise a wide, flat meplat projectile, it needs to be used in firearms that are designed for close range work or- in cartridges which already have such low velocity, that trajectory is not greatly effected by bullet meplat design.
Historically, U.S Gun writer Elmer Keith was the first hunter to both study and publish the effects of a wide, flat meplat, non expanding projectile used on game. There were definitely other hunters and ballisticians experimenting before him but it was Keith and his tenacious nature that made the wide, flat meplat into a 20th century issue. Keith pioneered the design of a flat point 250 grain .44 calibre hard cast lead pojectile for his .44 special revolver in 1926 with results that would forever shape his opinions on hunting bullet design and forever influence his staunchest fans. Yet today, more than 80 years later, the subject of metplat shape and surface area is largely untapped
In plain terms, a wide flat pointed solid non expanding bullet, even if driven at handgun velocities, creates disprortionate to calibre wounding where a pointed, non expanding bullet would create a calibre sized wound. It is this dis-proportinate to calibre wounding that is of most interest to the hunter as it is this mechanism that promotes fast clean killing.
The physics involved in wide/ flat meplat wounding are very simple, the flat point meets huge resistance on impact causing the water in flesh to be forced violently away from the path of the bullet, this in turn results in broad wounding. At velocities above 1700fps and using a wide calibre, the .45-70 (.458") which this article is focused around, entry wounds using the widest possible meplat may be up to an inch in diameter with the wound channel slightly larger and remaining the same diameter for several feet. This opens up both the possibility of both broad wounding with solid projectiles combined with penetration not normally available with expanding type projectiles.
At this point it must be noted that, the higher the impact velocity, the greater the resistance. This occurs simply because the water molecules of the animal, cannot move away from the flat point bullet at relative speeds. So as velocity is increased, wound channels increase in diameter however penetration may not necessarily be deeper due to increased resistance at the target. Pointed FMJ projectiles do not seem to show much difference in wounding or penetration at varied velocities. As an example, a 147 grain 7.62 FMJ projectile fired from a .300 Win mag creates the same size permanent wound cavity as it does when fired from a .308 Win rifle. Some extra bruising does occur throughout the lungs however the actual speed of killing remains unchanged and kills with this projectile on medium game are generally slow.
Oddly, although entry wounds with wide flat meplat bullets are almost always large, non expanding bullets of this style do not seem to produce hydrostatic shock at the typically low muzzle velocities produced by big bore rifle and handgun cartridges. By hydrostatic shock, I mean the ability of the projectile to send a shock wave through the ribs and into the spine with such speed that the central nervous system shuts down the brain (temporary coma) during which time the vitals bleed out before the animal regains conciousness, giving the illusion that it has died 'instantly'.
Due to the fact that slow, non expanding wide, flat meplat projectiles do not produce any shock effect whatsoever, when using such bullets on dangerous game, hunters are advised to expect clean but delayed kills, a potentially deadly situation. Flat meplat non expanding bullets definitely give optimum results when striking major bones. When bones are hit, wound channels change from being consistant 1 to 2" wide wound channels to much more dramatic wounding. When this type of bullet strikes bone, the fragments that separate tend to be very large and incapacitating.
On average, again using the .45-70, wound channels created by flat meplat non expanding projectiles are about four times the size of the original .458" calibre hard cast bullet however expanding projectiles in .45-70 will normally produce internal wounds twelve times their original bullet diameter at close ranges and in high velocity loadings. Needless to say, expanding bullets are capable of producing faster kills. The use of a flat meplat non expanding bullet therfore requires careful consideration.
As stated, wide, flat meplat non expanding projectiles are typically slow or 'delayed' killers, even with good shot placement. This can pose serious problems when hunting large dangerous game. Worse still, in a moment of intense stress such as during a charge, poor shot placement by the hunter may lead to minimal wounding where a premium controlled expanding bullet may have been capable of more devastating wounds. It is a tough call, on frontal shots, the flat meplat non expanding projectile driven at moderate velocities, even if missing the vitals or forwards locomotive muscles and bones, still has the potential to smash pelvis and rear leg bones. Several reports indicate that hunters have indeed anchored large heavy animals in this way.
There is not only great room for experimentation with wide meplat bullets, but also expanding wide meplat bullets, an area which most manufacturers have yet to tap into. Authorities on the subject of wide meplats generally view .300" as being the minimum and .360" being the maximum practical width for meplats of .458" calibre. These measurements prove true when tested on game and the difference that an .060" (1.5mm) increase in meplat width makes to wounding and fast killing is often dramatic.
Below are a series of photos taken from a simple days experimentation with the .45-70. The game hunted on this occasion were simply feral billy goats due to the fact that it allowed me to repeat tests over and over in a semi controlled environment- close range bush hunting where the abundance of game allowed me to take identical shots throughout a series of gullies. Average body weights for these animals was 50kg (110lb) and all animals were shot when relaxed, none were adrenalised before the shot.
The projectile used in the experiment was the Speer 400 grain flat soft point, a very good allrounder for a huge variety of game including light/ lean game up to bodyweights of around 320kg (700lb). What made this experiment interesting is that animals were taken with the Speer bullet fired backwards as well as forwards. Kids, don't try this at home. While the Speer is one of the few projectiles which already offers a generously wide/ flat meplat, firing it backwards offered the maximum width meplat possible for the .45-70. The rifle (a custom bolt action) was also tested for accuracy and surprisingly, the backwards Speer grouped well and showed no signs of instabilty when observing the uniformity of bullet holes through paper.
The purpose of these experiments was really to determine speed of killing. In recent years there has been a lot of argument throught various public hunting forums as to the effectiveness of a wide flat meplat bullet travelling at low velocity for use on dangerous game in comparison to both a low velocity expanding projectile and at the other extreme, high velocity big bores such as the .460 Weatherby. Each of these has its strengths and weaknesses. The most important factor is that the hunter be provided with correct information as to what to expect when each load is used on game and how to utilise projectiles, exploiting the strengths of the projectile designs.
For my own part, I much prefer the extremes, using a high velocity big bore. I am not so much a fan of clean but slow kills, regardless of deep penetration. I have used the .45-70 and the 400 grain Speer to take wild cattle but much prefer something a whole bunch faster. High velocity and careful shot placement gives me great satisfaction but I am also aware that penetration may be sacrificed on angling shots. For others, a classic big bore cartridge from yester year is far more thrilling to use than my latest ten million magnum. Variety is certainly the spice of life.
As for wide, flat meplats in small bores, the greatest problem with wide meplats in the small bores is that ballistic co-efficients are greatly reduced, especially with regard to wind drift. Such changes tend to handicap otherwise flat shooting cartridges with the negatives outweighing any other benefits. Secondly, most small bores have high velocity in their favor, a major proponant in wide wound channel creation negating any need for increased performance. Perhaps the only advantage of using wide meplat non expanding projectiles in high velocity small bores would be in the design of full metal jacket projectiles in 7mm and .30 calibre for follow up shots on large game. In military ammunition, a small flat point rather than a fully pointed FMJ jacket does make a notable difference in stopping power, the ramifications are obvious.
Some examples of flat meplats disscussed throughout the small bore texts of the book Hunting cartridges of the World include- the Norma Vulcan in 6.5mm, 7mm and .30 calibre along with several brands of flat point .30-30 bullets. Of these, the Vulcan in all calibres and the .30-30 Sierra projectiles showed very good results.
Wide meplats really start to become more and more useful in the .358" calibre and upwards. Many medium bores are utilised at limited ranges of up to 200 to 250 yards and in such cases, the poor BC's created by wide meplats is of little handicap. By simply changing from a pointed soft point to a round nose soft point, many cartridges become fast killers on light or lean game where before the bullet may have carried too much momentum, failing to impart its energy. Results of the change in bullet style in the medium bores are often dramatic on all manner of game. That said, only a very few, mostly custom bullet makers, offer true flat point medium bore projectiles. Most manufacturers offer round nose bullets, nevertheless, the Woodleigh Welcore, mentioned throughout the medium bore texts, is a good example of a fast killing round nose bullet in comparison to its pointed counterpart. Both of the Woodleigh designs have their strengths which are explained in the medium and big bore texts.
As discussed, Elmer Keith was one of the very few hunter/ researchers that experimented with wide meplats in large calibres. Keith's work revolved around experiments in the calibres .38 (.357"), .44 (.430") and .45 (.451") with non expanding bullets. Very few others have experimented with big bore wide meplats, most notably Garret Cartridges inc, experimenting with both .430" and .458" calibre bullets while Lyman, Lee and RCBS offer Keith style bullet moulds. Speer are the only manufacturer to offer a wide meplat jacketed soft point bullet which comes in the form of the .45-70 400 grain jacketed flat point. Apart from this, the market remains open to the development of wide, flat meplat expanding soft nose bullets.
For those who wish to use a hard cast, non expanding, wide meplat big bore bullet for hunting large, heavy bodied dangerous game, shot placement is the key to optimum results. The hunter must attempt to destroy the autonomus plexus of game if possible, with the first shot. For many hunters, this is not a natural point of aim. The autonomus plexus is located at the junction of the heart and lungs in all mammals and viewed broad side, it is located at the ball joint intersection of the scapula and humerus bones. This joint is slightly forwards of the line of the front leg. That said, this point of aim is only applicable for broadside shots. Front on, the autonomus plexus is located at the center of the chest but slightly high, from quartering angles, the hunter must be able to visualize the autonomus plexus and aim shots accordingly. For newer hunters, performing these mental checks in the field can end up overwhelming, resulting in a generalized chest shot. The only way to avoid this, prior to a big game hunt, is to practice over and over, either mentally (visualization) or when hunting lesser game or even on small game, using a .22lr.
Game killing, vital zones
The lungsAll of a mammals blood must pass through the lungs where it can be released of carbon dioxide and enriched with oxygen to fuel the body. Blood leaves the heart situated below the lungs through the pulmonary artery which becomes a network of arteries feeding into the blood capillaries of the lungs. Once enriched with oxygen, the blood then travels back to the heart, then out through the aorta artery to be pumped throughout the body. Although associated with the respiratory system, destruction of the lungs is one of the fastest ways to bleed out the circulatory system ensuring a quick clean kill. On top of this, the lungs present the largest, safest target for the hunter.
As viewed broadside, a deer’s lungs begin at the intersection of the scapular and humerus bones of the foreleg. In height, the heaviest portions of the lungs are situated at the centre of the chest, in line with the lower foreleg. The lungs reach to within an inch of the spine, which is not to be confused with the top of the fur line as above the spine the dorsal vertebrae extend upwards by at least 3 inches. At their lowest point, the lungs are again around 3 inches above the line of the brisket and are thinner to accommodate the heart. Behind the foreleg, the bottom of the lungs extend little more than 2 inches before tapering upwards sharply , running out to thin edges just short of the last few ribs.
Based on a Whitetail deer sized animal viewed broadside, head to the right and using the straight lower leg as a centre line, a shot to the centre of the chest will destroy the heaviest portion of the lungs ensuring a fast bleed and therefore fast kill. A shot 3 inches above centre at 12 o’clock will destroy the upper lungs, an equally fast kill however; it is possible to strike too high between the lungs and spine or the dorsal vertebrae above causing instant collapse followed by recovery after a few seconds leading to escape and a slow kill.
Approximately 2 to 3 inches forwards of dead centre at 3 o’clock is the ball joint intersection of the scapular and humerus bones. A shot here not only destroys the forward portions of the lungs and hopefully the bones of the legs but also the autonomic plexus, a major network of nerves feeding into the chest cavity from the neck which, when hit soundly, causes instant collapse and death. This is the most useful aiming point when using medium capacity cartridges that have enough bullet weight to penetrate bone but not enough velocity to initiate hydrostatic shock or wide wounding. It is also a good point of aim for those who wish to refine their shooting skills.
A shot striking around 3 inches low at 6 o’clock strikes the bottom of the lungs and the arteries feeding into them from the heart, a reasonably fast killing shot but if it is slightly too low the shot may severe the heart (see heart) or simply the brisket, both slow killing shots. A shot striking 3 to 5 inches to the rear of the chest at 9 o’clock from dead centre is a slow killing shot unless the cartridge used has immense wounding potential. High power cartridges may damage the rear portions of the lungs as well as rupturing the diaphragm however, animals usually run at least as far as when heart shot. The rear thin portions of the lungs, directly behind the foreleg tapering up and along the ribs, are considered a slow bleeding area and therefore a larger amount of tissue must be destroyed to effect a fast kill. High velocity cartridges such as the .270 .280 and .30-06 win out over smaller, milder calibers of the .243 and 6.5 class for fast killing in this area. All of these examples are based on smaller medium sized game; larger animals present a larger target area and therefore create an extra margin for error.
The greatest method of creating Spinal shock transfer is through shots that strike the upper half of the chest. Below center, the ribs are a long way from the spine therefore mid to low shots sometimes fail to produce shock, such as the heart shock and game may cover considerable ground after such a shot.
A true rear lung shot or ‘meat saver’ should be taken with the foresight or crosshair aimed snugly behind the foreleg as within a couple of inches back, the lungs and ribs have already tapered upwards. The cross body meat saver shot is especially important to .22 centre fire users as it allows the projectile to deliver more energy to the lungs, avoiding bullet failure on the shoulder. Just as suitable is the soft junction between the shoulder and neck giving access to the lungs when game are quartering on as well as the nerves and arteries of the lower neck when broadside.
In pigs, the layout of the lungs is very deceptive; the curvature of the spine at the shoulder is very low with the top third of the chest as viewed from the side consisting of dorsal vertebrae, cartilage and muscle to power the head. For this reason, it is important to consider the lower two thirds of the pigs shoulder as a vital zone. The lungs are completely protected by the shoulder, tapering up almost vertically at the rearmost line of the foreleg with the diaphragm positioned directly behind the foreleg. Therefore not only is the vital zone limited to the lower two thirds of the chest, but also from the foreleg forwards including the arteries and veins of the neck. That said, a shot high (below the spine) and flush behind the shoulder will strike the rear lungs and can be a good killer but slight error may result in either a liver or a gut shot.
Upon gutting any game animal, it is worth studying the causes of death and condition of each organ. A good lung shot will leave the chest cavity full of congealed blood; the meat will be well bled out for the table negating the necessity to bleed out the arteries of the neck.
The heartAt the bottom of the chest, starting in line with the foreleg and ending 3 to 4 inches behind, lies the heart. The heart is responsible for pumping oxygen and nutrient rich blood to all parts of the body. Despite popular belief, the heart is not a good target for a fast killing shot. A heart shot will allow oxygen rich blood to be locked in the brain and locomotive muscles, allowing an animal to run long distances before collapsing. Shots falling low, into the heart may allow deer to run as much as a hundred yards often making tracking difficult.
The liverViewed broadside, the liver appears roughly in the middle of an animal. The liver hangs from the spine descending roughly halfway down, between the paunch and the diaphragm. The liver is responsible for metabolizing fats, proteins and carbohydrates into the blood. It also detoxifies the blood as well as performing many other functions. The Hepatic artery and vein pass through the liver although most of the liver can be considered a fast bleeding area.
The liver is a very small target and difficult to hit deliberately and for this reason the liver should not be regarded as an aiming point. However, the liver is often hit when game step forwards as the hunter takes the shot, or are running when the shot is taken, or when angling shots are taken. If the liver is destroyed an animal may run someway (usually quite stiffly) but will succumb quickly. Often less experienced hunters will simply divide the animal into four quarters with the scope crosshairs and pull the trigger, the result is either a fluke hit to the liver or else a wounding gut shot. Directly behind the liver and attached to the spine are the kidneys, responsible for filtering waste from the blood. The kidneys are slow bleeding organs and if wounded result in a slow death.
The abdominal cavityThe paunch is a slow killing zone. Shots to any part of the paunch cause digestive acids to pass into the blood stream. This leads to blood poisoning with death occurring several hours later. Visible indicators of a gut shot include a deep audible ‘whock’ sound as the bullet strikes and game will often rear up on hind legs before running, although it is not uncommon to see no sign of a hit at all. Large caliber potent cartridges loaded with unusually soft fast expanding projectiles can sometimes anchor game through the destruction of such a large amount of the gut that the body shuts down and goes into coma. However other cartridges usually allow game to escape leaving no blood trail and often no gut fiber, trail either, leaving the animal to endure a slow painful death.
The neckFrom the lungs forwards, arteries, veins and nerves of the chest cavity taper into the neck. The vital systems of the neck include the spine and spinal nerves, the carterid artery transporting blood to the head and the jugular vein transporting blood back to the heart, Destruction of any of these causes a fast kill and even if the spine is not hit, suitable projectiles will often transfer shock to the spine causing instant collapse. That said,
during the roar or rut, the neck of a male game animal can become very swollen and shots to the neck may result in delayed kills. This is largely due to the fact that the arteries and veins are incredibly elastic, sometimes remaining intact after the bullet has passed through the neck.
Typically, projectiles that create an explosive wound have more of a chance of destroying both the spine and circulatory system however; it is often impractical to hunt with such loads. The neck shot should be limited to ranges for which a margin of accuracy can be guaranteed. Broadside shots are best placed to strike just below the spine which, for rifles sighted 3 inches high at 100 yards, means a hold on the bottom line of the neck on medium sized game at ranges of between 50 and 200 yards.
The headThere are two aspects of the nervous system. The Peripheral system refers to all of the branches of nerves throughout the body acting as sensory organs monitoring internal and external environments, responding to stimuli and conducting impulses. The central nervous system (CNS) refers to the brain and the highway of all information, the spinal cord. The destruction of the brain or spinal cord as far back as the shoulder causes instant death by simply shutting down the vital systems of the body (apart from the self-regulating heart).
Far from the ideal shot due to the accuracy required, the head shot is best suited to close ranges. The head shot is best utilized in bush hunting situations or for finishing a wounded animal obscured by long grass. Suitable points of aim include the ear or between the ear and eye as viewed broadside; from the front, between the eyes if the rifle is sighted high or slightly above the eyes if the rifle is sighted dead on.
These points of aim are suitable beyond 20 yards but at closer ranges of between 10 and 15 yards the bullet is traveling atleast 1.5 inches below the centre of the crosshair on a scoped rifle due to the physical height difference between the scope and the bore below. At these ranges, if the point of aim is at the the ear and the shot hits low, the bullet will often strike the jaw allowing the animal to escape and suffer a very long, slow, painful death. Although scopes have given us superior accuracy over open sights, their added height can cause confusion for close range head shots. A simple method for close range or coup de grace shots out to 15 yards is to place the horizontal crosshair flat across the top of the head, definitely not a shot for trophy hunters. While certainly a fast killing shot, a lot can and does often go wrong with head shots. The head shot is certainly one of the least ethical points of aim.
Game at varying anglesThe quartering away shot describes a shot taken at an animal facing partially away from the hunter. In order to destroy the lungs for a fast kill the shot may have to be placed to pass through the paunch or rear ribs. Solidly packed gut fiber or in-line ribs may be encountered as the bullet makes its journey to the lungs therefore bullet construction is a vital factor. Long for caliber bullets, offering high sectional densities and straight line penetration win out over light super explosive bullets on this shot and the more powerful of cartridges will often transfer shock to the spine, after passing through the lungs and impacting the frontal ribs of the offside. A quartering on shot describes a shot taken at an animal partially facing the hunter. When angling shots through the front quarter into the lungs, the point of the shoulder is often the best place to aim. However if the animal is facing slightly more toward the hunter the point of aim can be placed on the crease between the brisket and the shoulder muscle. This shot if true will strike the main nerve centers as well as the lungs, pole axing the animal for sure.
From the front, even at close ranges, shots placed squarely in the middle of the chest can sometimes pass between and fail to destroy the lungs. A large wound channel can minimize such failure however, as a power level example, it is not uncommon for some brands of .270win factory ammunition to cause slow or unrecovered kills on animals as light as 40 kg (80lb) when hit this way at close range. Where doubt exists, a more reliable result can be obtained by either aiming slightly off center or aiming higher towards the neck and spine.
Tail on shotsAlso known as the Texas heart shot, the tail on shot refers to the common occurrence when deerstalking of finding an animal facing directly away from the hunter but usually looking back towards the hunter, poised for flight. This shot is considered unethical in Europe but is regarded as acceptable in the USA Australia and NZ.
There are two distinct methods of applying the tail on shot relative to cartridge power. With lighter cartridges, a proven method is to angle the shot to destroy the spine and follow through quickly with a finishing shot. With heavier calibers, it is possible to achieve full length penetration, destroying the lungs as well as transferring shock to the spine via the frontal ribs causing instant poleax. Bullet construction is much more important than sectional density for this shot and many projectiles fail under these circumstances, even those seemingly purpose built for the job such as heavy round nosed bullets of large caliber.
Discuss this article or ask a question on the forum here
Copyright © 2007-2011 Terminal Ballistics Research, Ballisticstudies.com