As anyone who’s googled “Taurus Judge” knows, there’s been an ongoing (and frequently vitriolic) debate over how effective a Judge is, as a defensive weapon.  Most will acknowledge that the .45 Colt is an effective round, but there’s tremendous controversy over the effectiveness of buckshot from a Judge.

I attempted to address this in my video review of the Judge Public Defender Part 2: As A Shotgun, below:

However, I’m still exploring ways to quantify just how effective a hit from the handgun shotgun revolver would be.  We know that the Judge (with the proper ammo) can penetrate very deeply; in my own ballistics gelatin tests and in tests from others, we’ve seen well in excess of 16″ of penetration, even up to 20″.  But how do four .36-caliber buckshot balls compare, in terms of incapacitating effectiveness, against an expanding hollowpoint from something like a .45 ACP?  Is there even any way to compare them?

Comparing the effectiveness of different cartridges, and finding a way to quantify their relative effectiveness, has been a popular topic since at least 1904, when the Thompson-LaGarde tests were conducted to find out how many shots from various calibers it took to incapacitate a steer.  Since then we’ve seen a variety of “factors” or “formulas”, such as the TKO (“Taylor Knock Out Factor”) or the Marshall-Sanow “One Shot Stop” percentage, all attempting to classify or compare relative cartridge power, and all substantially flawed in one way or another.  The Thompson-LaGarde steer tests are in fact very valid for hunters of large animals over 1,000 pounds, but for the purpose of defending against an attacking human they’re much less relevant because they’re based on dropping massive animals.  The TKO factor is highly unscientific and was never meant to be applied to handgun rounds anyway, and the Marshall-Sanow database has been seriously discredited by several leading members of the IWBA.

So where can we turn to get an impartial, scientific, quantifiable assessment of the damaging factor and the incapacitating capability of a particular handgun round?  As in — how can we reliably speculate on how effective a bullet will be in stopping an attacker?

The FBI, the International Wound Ballistics Association, and leading trauma surgeons, combat medics, emergency-room physicians and others came together in multiple summits and determined, by consensus, that a bullet needs to be able to penetrate at least 12″, and ideally no more than 18″, in order to be able to inflict an incapacitating wound.  You can read the FBI report here.

The conclusions from the FBI report are pretty simple to grasp — a bullet needs to penetrate deep enough to hit the vital organs, and the larger the bullet, the more tissue will be damaged, so bigger = better, so long as adequate penetration is achieved first.

However, that doesn’t help us determine how to rank bullets against each other in terms of comparative effectiveness.  The FBI report gives us a metric to measure “pass/fail” of any particular bullet, but in reality that’s a pretty strict measuring stick — a bullet that penetrates 11.5″ would be classified as a “fail” even though it should seem pretty obvious that an 11.5″ penetrating bullet is by no means guaranteed to fail.  It won’t be as effective as a 14″-penetrating bullet, sure, but that doesn’t mean it would be totally ineffective either!

So how can we address the popular need of wanting to be able to determine, classify, and compare bullet effectiveness?  Duncan MacPherson, NASA rocket scientist and founding member of the International Wound Ballistics Association, publishes his attempt at a Wound Trama Incapacitation (WTI) factor in his excellent book “Bullet Penetration: Modeling the Dynamics and the Incapacitation Resulting from Wound Trauma“.  Unfortunately the book is out of print, and the only way to get a copy is to scour ebay or used bookstores or buy a used copy off Amazon, but if you’re interested in the subject, it’s a fascinating examination of what really, really happens when a bullet impacts flesh.

In the last chapter of the book, MacPherson presents a mathematical model for determining the incapacitation likelihood of any particular cartridge.  Now, by “incapacitation”, he means damaging the attacker so much that the attacker is forced to stop attacking.  MacPherson approaches it from the medically-validated aspect of how much tissue is damaged, and how deeply the bullet penetrates.  He doesn’t rely on mysticism like “energy dumps” or “hydrostatic shock” or other non-quantifiable and highly disputed concepts; instead he relies on the science of wound ballistics, the examination of trauma victims, the realities of bullet hits, and the use of science to determine how much damage a particular bullet will do, and how much damage a typical human attacker could withstand before their body forces them to shut down.

Taking 300 pages of utterly brilliant mathematical modeling and physical science and boiling it all together and distilling it down to a simple number is a bold task, but once all is said and done, the conclusion reached is that a bullet that penetrates deeply enough and destroys 40 grams of tissue is a pretty good candidate for incapacitating a target.  There’s much more to it than that, of course, and if you want to truly understand it you’ll have to get the book, but the model MacPherson uses assigns different values and weighting to different penetration depths, it takes into account velocities, it assigns different factors to hollowpoints, or wadcutters, or roundnose projectiles, etc.  It’s quite detailed and excellently done, but once it’s all boiled down and accurately accounted for, the net result is: how much tissue is disrupted?  If it’s a big-enough hit, and deep enough, it stands a good chance of incapacitating the attacker.

Based on his model, I’ve calculated the mass of tissue destroyed for my favorite rounds from two Judges, the Public Defender (the smallest of Judges and the “weakest”) and the Raging Judge Magnum (the largest of Judges and the “most powerful” Judge pistol).

The two rounds I’m using are the Federal 410 Handgun 000 buckshot, and the NobelSport .40-caliber buckshot.

In the Federal .410 000 round, there are four pellets of .36″ diameter and 63.5 grains apiece in the 2.5″ shell, for a total payload of 254 grains of lead.  In the 3″ shell, there’s an additional pellet, bringing the lead payload up to almost 318 grains.

In the NobelSport cartridge, there are three pellets of .40″ diameter and 90 grains apiece in the 2.5″ shell, for a total payload of 270 grains of lead.  In the 3″ shell there’s an additional pellet, bringing the  total lead payload up to 360 grains(!)

Using the proper mathematical formula, the proper weighting for penetration, and the diameter of the bullets themselves, yields the following tissue damage results:

2.5″ Nobel:  66 grams

2.5″ Federal: 65.6 grams

3″ Nobel: 84 grams

3″ Federal: 82 grams

Each of these is well in excess of MacPherson’s desired threshold of 40 grams; the 3″ shells are actually over double the level necessary!  Now, does this mean that each shot from a Judge will result in immediate incapacitation of an attacker? Of course not, there are never any “guarantees”, but in dealing with averages, it does mean that the shots from a Judge will likely be quite effective indeed.  It should at least address the silly and baseless internet argument of “buckshot will just bounce off an attacker”.

For comparison, I ran a calculation on a .45 ACP +P round, Hornady Critical Duty 220 grain, at 951 fps, and 15″ of penetration.  According to the Schwartz Quantitative Ammunition Selection formula for calculating the mass of the permanent wound cavity, and then applying the MacPherson WTI calculations, we get 69.82 grams of tissue disrupted.  That’s right on par with the 2.5″ buckshot shells, and not quite as much as the 3″ shells.  A good round of .45 ACP has long been known as an effective manstopper; the Judge 2.5″ rounds don’t destroy any more tissue despite having multiple projectiles, but on the other hand — they have multiple projectiles, which gives them multiple wound paths, which raises the prospect of turning a near-miss into a hit on a vital structure in the attacker’s body.  The 3″ shells do provide more tissue disruption than the single .45 ACP hollowpoint, but not significantly more; their main advantage is not so much in the 19% additional tissue they disrupt, but in that they create four or five wound paths instead of one.  Again, that gives more opportunity for a near-miss to become a hit.

So how effective is a Judge in stopping an attacker? Each blast from the 2.5″ shotgun shells (presuming you’re using the right ammo!) will disrupt as much tissue as a premium .45 ACP hollowpoint, but will give you three or four separate wound tracks, thus giving you three or four chances at hitting a critical or vital structure (such as the heart, major artery, or central nervous system).  And if you’re using 3″ shells, you’ll get around 20% more tissue disruption than the 2.5″ shells, and another projectile for yet another opportunity at hitting something vital.

While we can’t predict the actual results in any actual individual shooting scenario, we can reasonably draw a broad conclusion: would a Judge with Federal .410 Handgun 000 buckshot or NobelSport buckshot be an effective manstopper? The test results say “hell yes.”