Pages

Wednesday, March 4, 2015

Using Wadcutters for Concealed Carry (Update)

Left to right: lead round-nose, wadcutter, and hollow-point (Wikipedia)
Caleb at Gun Nuts Media explains why he uses wadcutters in a light-weight, snub nosed revolver. Basically, it comes down to control, accuracy, and penetration.

Wadcutters, as you probably know, are flat tipped bullets intended to cut a nice clean hole in a paper target. Since they are intended for target practice, they are generally loaded with a smaller load of powder.  Back in the day, before quality hollow-point ammunition was available, many police and self-defense shooters recommended using wad-cutters (or semi-wad-cutters) because of the belief that, just as they do with the paper target, the wad-cutter bullets would also cut a clean hole in a flesh and bone target promoting rapid bleeding.

Whether that is true or not, there is no doubt that they would have been more effective than round-nosed bullets. The reason for this has to do with the flat face of the bullet--the meplat of the bullet. Nathan Foster discusses this in his article, "The Effects Of The Meplat On Terminal Ballistics." First, some background:
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. ... 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 [sic] 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 in turn 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. 
Foster notes that Elmer Keith experimented with flat-nosed projectiles for hunting, and was a big-fan of such projectiles.

Anyway, the key point from the article is this:
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.
Underline added. Read the whole thing.

Update (3/5/2015): Decided to change the title as the original title was too awkward.

No comments:

Post a Comment