Tuesday, April 17, 2012

Scenario Consultation: Here There Be Dragons; A Brief Excursion into the Fantasy Genre


Over the years, I’ve gotten a lot of interesting questions from my shooting class students and writers who attend my firearms technology workshops.  One of the strangest, or at least the most unexpected came at me last Saturday.  I was explaining the “anatomy of a gunshot wound,” and going into clinical, if not gory, detail about permanent cavities, temporary stretch cavities and the relative merits of penetration versus velocity when one of the attendees stopped me and asked a question.

“What kind of handgun would you use to slay a dragon?”

Not the subject of the question.
Now, just so we’re on the same page here, I’m ME.  And, given that I’m me, the first thing I thought of was the M47 Dragon antitank guided missile (ATGM).  After all, nobody could be seriously asking about how to kill a large mythical reptile with a pistol.  Nobody, that is, except for a romantic fantasy author.

As you might have guessed, an obsolete missile was not the type of dragon that was the subject of the question.  A moment later, it registered on me.  The question was serious.  The nice lady wanted to know what handgun I would recommend for dragon slaying.
  
I'm supposed to service one of these with a PISTOL?
My initial response, was that the more appropriate firearm for dragon slaying was a rifle.  And not just any rifle.  Something that fires a big, heavy, solid bullet a velocity approaching 3,000 feet per second.  The two cartridges that came to mind immediately were the .460 Weatherby Magnum, which will launch a 500 grain bullet at around 2,700 feet per second, generating about 8,100 foot pounds of energy, and the .50 Browning Machine Gun, which will fire an 800 grain Barnes Solid bullet at right around 3,000 feet per second for a stunning 16,000 foot pounds of energy.

BIG bullets.  .50 BMG is on the left.
The reason for my selection of these behemoth cartridges has to do with dragon physiology.  Ok, purists, with my assumption about dragon physiology...(with thanks to www.draconian.com).   
Let’s take a medium size dragon, say about 20 feet long, with a wingspan of about 35 feet.  This dragon has three key physiological characteristics that matter to the ballistician.  First, the dragon’s exterior is covered in scales that, after the first year of the dragon’s life, become as tough and as hard as a mid-grade steel.  For reference, many surgical instruments are made from mid-grade stainless steels.  Next, the dragon’s skeleton is strong, but hollow and lightweight.  It features a thick sternum bone that protects the dragon’s chest, heart and lungs.  Finally, the dragon’s muscles are corded and thick, providing additional protection to the beast’s internal organs.  Defeating a dragon means punching through the scales, shattering the sternum, and digging a deep trough through tough muscle to penetrate and fatally damage the heart.  Most rifle cartridges won’t meet these requirements.

Not cutting it.  .454 Casull ammo.
I dutifully explained this to my audience.  Unfortunately, they were having nothing of it.  The storyline called for the hero to defeat the dragon with a pistol.  In case any of you were wondering, when it comes to fantasy authors, storyline trumps practical weaponology every day of the week.  The dragon would simply have to fall to a pistol.  The question was HOW.  Pistol cartridges, even the mighty .454 Casull, simply don’t pack enough energy to perforate a dragon’s scales and then penetrate deeply enough to damage the heart muscles.

The more I thought about it, the more frustrated I got.  Penetration is directly proportional to a projectile’s kinetic energy.  Kinetic energy is calculated as ½ Mass(Velocity2).  When applied to a firearm, energy is described using a relevant measure of force, such as foot-pounds.  To derive foot pounds from the ½ Mass(Velocity2) formula, we adapt it by dividing it by a constant, which is 450,400.  The 450,400 represents 7,000 grains (bullet weights are measured in grains, 7,000 grains equal one pound) multiplied by the acceleration of gravity (32.17 feet per second) multiplied by two to get rid of the fraction at the beginning of the equation.  The resulting equation is Energy = (Mass*Velocity2)/450400.  Remember that .50 BMG round that generated 16,000 foot-pounds of energy?  Next to that, the mighty .454 Casull, and its 1,800 foot-pounds is a featherweight.  There was just no way a pistol round was going to smash through scales, sternum and a couple of feet worth of corded muscle.

Obsolete.  Boys .55 cal. Antitank Rifle
However, the more I thought of it, the more I focused on the word “kinetic.”  If only there was a way that the projectile could cut its way through instead of punching a hole by sheer force.  And then it hit me.  This was exactly the same problem faced by infantry during World War Two.  In the early part of the war, man-portable infantry antitank weapons, such as antitank rifles, were a fair match against the relatively thin-skinned armored vehicles of the day.  However, by 1942, tanks were being produced with significantly thicker armor, creating a conundrum for the infantry:  Weapons based on kinetic energy principles that could punch through a tank’s armor were simply too heavy to be carried by one soldier, and kinetic energy weapons that a soldier could carry just wouldn’t damage the tank.

The answer was to abandon kinetic energy generated by projectile impact velocity in favor of kinetic energy generated by explosive blast.  Specifically, kinetic energy generated by the use of a shaped charge.  A shaped, or “hollow” charge is an explosive charge that has been shaped to focus the explosive’s energy on a very precise point on the target surface.  The net effect of focusing the energy is penetration of seven to ten times the diameter of the original explosive charge through steel armor plate and much, much further through less tough materials.  

A typical shaped charge projectile consists of a solid cylinder of explosive with a metal-lined conical hollow in one end and a central detonator at the other end.  If the hollow area is properly shaped, the enormous pressure generated by the detonation of the explosive drives the liner in the hollow cavity inward to collapse upon its central axis.  This multi-axis collapse forms and projects a high-velocity jet of metal forward along the axis.  The jet's velocity is immense, with most of it moving at between 23,000 and 46,000 feet per second.  At these speeds, the jet and armor take on the characteristics of incompressible fluids, and the jet effectively squirts through the armor. Once inside the armor, the superheated jet continues to penetrate, and in the process, sprays the interior surfaces with burning, molten pieces of metal.
 
1) Ballistic cover, 2) Cavity, 3) Metal Liner, 4) Detonator, 5) Explosive, 6) Trigger 
US Bazooka - Shaped Charge Principle
 A projectile carrying a shaped charge is little more than a cargo device or bus whose responsibility is to get the charge to the target surface.  Since velocity doesn’t matter, propelling charges can be much smaller and, as a result, can be contained and controlled in a man-portable device.  The American “Bazooka,” the British PIAT (“Projector, Infantry, Antitank”) and the German “Panzerfaust” were all lightweight anti-armor devices that could be carried by a single soldier whose relatively low velocity projectiles delivered shaped charge warheads to the target.

MPAT - Fins pop out on firing.
Now that I had the answer as to how to slay a dragon, I needed to devise a launcher and delivery system for the shaped charge payload.  The obvious choice was a shortened, double barreled twelve gauge shotgun, a la Mad Max.  A specialized shell launching what was effectively a miniaturized version of the shaped charge based M830A1 Multi-Purpose Anti-Tank (MPAT, pronounced “em-pat”) would be devised.  The M830A1 is fin stabilized, so a significant degree of accuracy could be expected.  The obvious choice, however, lacked a degree of style and panache.  In other words, it just wasn’t cool enough to pique my gun-geek factor.

What I needed was something that could deliver a twelve gauge shell’s payload from a pistol platform and, meet my demanding technical, aesthetic and “intangible” (read that “gun geek”) standards.  After some thought, I identified the LeMat revolver as my ideal point of departure.

LeMat Revolver
The LeMat was a .42 caliber cap and ball revolver with a twist.  Instead of revolving around a central pin, like conventional revolvers, the LeMat’s cylinder revolved around a large central sixteen gauge shotgun barrel.  A quick flip allowed the shooter to choose between the pistol and the shotgun barrel.  Designed in 1855 by Dr. Jean Alexandre LeMat of New Orleans, it saw service with the Confederate Army, becoming a favorite of such famous Confederates as Generals Braxton Bragg, J.E.B Stuart and Richard Anderson.  In the end about 2,900 were produced.

Modern LeMat (Bienville Studios)
My improved LeMat would be a similar, but substantially different beast.  Crafted in stainless steel (you wouldn’t want the finish damaged when dragon blood gets all over it, would you?), with a six or eight shot cylinder rotating around a central twelve gauge barrel, it would be double action and have adjustable sights.  Barrel length would be six inches, it would be available in .454 Casull, and the sights would be optimized for the 360 grain Cor-Bon Hunter Flat Point Penetrator ammunition. Both barrels would be ported for maximum control.

When confronted with a dragon, the hero would unholster, flip the selector to the shotgun barrel, and fire an MPAD (Multi-Purpose Anti-Dragon) shaped charge shell at the dragon’s chest.  The charge diameter of roughly 0.72” would yield a penetration in armor of 10 charge diameters, or about seven inches.  Since the dragon’s scales are approximately an inch thick, the blast jet will have little difficulty punching through the scale layer.  The sternum bone, being significantly less dense, will offer far less resistance, and the muscle layers will be cut through almost as if they weren’t there.  The destructive force of a 20,000+ foot per second blast jet will impact the dragon’s heart, and that’s all she wrote. 

Conclusion

The existence of dragons is debatable.  However, literature has provided a very consistent portrayal of their capabilities, biology and physiology.  With this data, and a bit of technology and engineering, the challenges of dragon defense with a handgun can be overcome.  At least for fantasy authors.  As for me, the next dragon I have to face will be my first!

Sunday, April 15, 2012

Scenario Consultation: American Police Sidearms in the 1950s

An author presented me with the following plotline query:  A Tulsa, Oklahoma police sergeant is murdered in 1957.  The murderer is another Tulsa policeman, and the murder was committed with a handgun connected to the murderer's police duties.  For the sake of historical accuracy, the author is interested in knowing what handguns were prevalent among police agencies during the late 1950s.

The Revolver is King

Colt Single Action Army
For about a century, from the late 19th century through the mid 1980s, the double action revolver reigned supreme as the law enforcement sidearm of choice in the United States.  While some law enforcement agencies opted for single action revolvers such as the Colt Single Action Army (or "Peacemaker"), or semiautomatic pistols like the Colt Government Model in either .45 ACP or .38 Super caliber or the Colt Model 1903 and Model 1908 "Pocket Hammerless" pistols in .32 ACP and .380 ACP respectively, these were very much the exception.  As a rule, the preponderance of American policemen, of all ranks, were armed with revolvers made by industry giants Colt and Smith & Wesson.
Colt Model 1903 Pocket Hammerless

Mid-Bores Predominate

At the end of the 19th century, it wasn't uncommon to find police service weapons chambered for relatively small bore or low powered cartridges such as the .32 Smith & Wesson Long or the .38 New Police.

(Trivia point:  The .38 New Police and the .38 Smith & Wesson are the same cartridge.  Colt, understandably, did not want to provide free advertising for their rival, Smith & Wesson, and so coined a new name!)

.38 Special Cartridges
This was to change in 1899 with the introduction of the smokeless propellant variant of the .38 Smith & Wesson Special (or .38 Special) cartridge.  It's important to note that prior to its respecification in 1972 by the American firearms industry standards organization, the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI), the .38 Special was a significantly higher performing cartridge.  The traditional loading for a .38 Special is a 158 grain lead round nose (LRN) bullet.  Ballistics on the modern, post-1972 loading have a muzzle velocity of between 750 and 780 feet per second, for a relatively mild energy of about 205 foot/pounds, approximating that of the .38 Long Colt and .38 Smith & Wesson cartridges it theoretically made obsolete. The pre-1972 loadings for the .38 Special were an entirely different matter.  They propelled the same 158 grain lead bullet about 200 feet per second faster - between 930 and 970 feet per second, and generated a muzzle energy of between 310 and 320 foot pounds.  While this level of performance certainly isn't .44 Magnum territory, it is respectable and  comparable to the performance of the 9mm Parabellum cartridges adopted by American police agencies in the 1980s and 1990s.

In 1930, Smith & Wesson began offering a variant of its large frame .44 Hand Ejector Third Model revolver chambered for a variant of the .38 Special called the .38/44 Heavy Duty.  The new cartridge, developed in cooperation with Remington, was called the .38/44 High Velocity. It used the .38 Special's case, but pushed the 158 grain bullet at around 1,115 feet per second, generating about 440 foot-pounds of energy.  In doing so, it offered direct competition to Colt's .38 Super pistols.

S&W .38/44 Heavy Duty
The .38/44 Heavy Duty sold well, and equipped many law enforcement personnel in the early to mid 1930's, but in 1935 Smith & Wesson and Winchester rendered the .38/44 obsolete with the introduction of the .357 Magnum cartridge.  This cartridge was similar to the .38 Special, but used a case 1/8" longer, and operated at almost twice the pressure, propelling the 158 grain bullet to almost 1,500 feet per second and generating a whopping 770 - 780 foot pounds of energy.

American law enforcement was thus well served with the medium bore .38 Special for everyday work and .357 Magnum when greater range or penetration (automobile doors for example) was required.  Consequently, both Colt and Smith & Wesson offered a number of revolvers chambered for these cartridges and geared toward law enforcement.  These revolvers would dominate the American law enforcement market until they were supplanted by semiautomatic pistols in the 1980s and 1990s.  The following is a brief survey of Colt and Smith & Wesson offerings that would have been popular with American police agencies in the late 1950s:


Colt

Colt Detective Special
Detective Special:  The Colt Detective Special was a small frame revolver chambered for  the .38 Special cartridge.  It was produced between 1927 and 1986, and was marketed as an easily concealable handgun suited for use by detectives, plain clothes policemen or other law enforcement requiring easily hidden firepower.  It was typically found with a two inch barrel and had a six round cylinder.




Colt Official Police
Official Police:  The Official Police was Colt's offering for the uniformed policeman's standard service weapon market.  This medium frame revolver was extremely prolific in the 1950s, and was produced between 1927 and 1969.  It could be found with barrels of four, five and six inches and had a six round cylinder.




Colt Police Positive Special
Police Positive Special:  The Police Positive Special was another Colt offering for the  standard service weapon market.  It was based on Colt's small frame (like the Detective Special) and, like the Official Police, was extremely prolific in the 1950s.  It was also long lived, being produced between 1908 and 1995.  It could be found with barrels of four and six inches and had a six round cylinder.

Smith & Wesson

S&W Military & Police
Military & Police Model 1905 4th Change:  The Smith & Wesson Military & Police (M&P) revolver could be the single most prolific revolver in history with some six million examples being produced.  This medium frame revolver was introduced in 1899 and is still in production.  In 1957, Smith & Wesson stopped using names for its products and assigned model numbers to existing products.  The .38 Special M&P became known as the Model 10.  Model 10s are found with two, two and a half, three, four, five and six inch barrels.  The M&P/Model 10 cylinder holds six rounds.

S&W Model 19
Model 19:  The Model 19 uses the same medium frame as the Model 10, but is chambered for the .357 Magnum cartridge.  It barely makes it into the running for this list as it was introduced to the Smith & Wesson line in 1957 (it's still in production).  Generally found with either a four or six inch barrel, the Model 19's cylinder holds 6 rounds.




S&W Registered Magnum
Model 27:  The .357 Magnum Model 27 was the first "Magnum" handgun ever produced.  It was introduced in 1935 as the "Registered Magnum," retitled in 1939 to the ".357 Magnum," and again in 1957 to the "Model 27." It is based on Smith & Wesson's large revolver frame and has been produced with three and a half, four, five, six, six and a half and eight and three eighths inch barrels.  Registered Magnum and .357 Magnum variants with three and a half inch barrels were very popular with the Federal Bureau of Investigation (FBI) and other law enforcement agencies in the period from the 1940s through the mid-1960s.

S&W Model 28 Highway Patrolman
Model 28:  Originally introduced as the "Highway Patrolman" in 1954, the Model 28 is identical to the Model 27 with the exception of the gun's finish.  Offered as a lower cost alternative to the Model 27, the Model 28 lacked the former's highly polished, mirror blued finish, opting for a matte finish on exterior surfaces that were not as polished.  Mechanically the two were identical, as was performance.
 

S&W Model 36 Chief's Special
Chief's Special:  The Chief's Special (the Model 36 after 1957) was Smith & Wesson's small frame response to the Colt Detective Special.  Introduced in 1950 and still in production, variants found in the mid to late 1950s would have been chambered for the .38 Special and equipped with a one and seven eighths inch barrel.  Unlike the Colts, the small frame Smith & Wessons have a five round cylinder.  The Chief's Special, ans the name implies, was marketed toward higher ranking police officers who wanted a smaller, lighter sidearm.

Thursday, April 12, 2012

Firearms, Hacking and Action Choreography Workshop


For those of you in and about the greater Cincinnati area, I will be presenting a one day workshop on firearms, hacking, and the choreography of action and violence sequences this Saturday, April 14.

The workshop will include modules on:

Introduction to Firearms & Ammunition;
Tactics, Techniques & Procedures;
Terminal Ballistics;
Hacking Cyber Crime;
The Choreography of Direct Action; and

a "hands on show and tell" to familiarize participants with modern revolvers, semiautomatic pistols and assault rifles.

The workshop will take place at the Kings Island Conference Center, 5691 Kings Island Drive Mason, OH 45040, from 10:00 AM to approximately 5:30 PM.

The workshop is sponsored by the Ohio Valley Romance Writers of America.

For more information on the workshop or to register, see:

http://ovrwa.com/april-2012/

Thanks!

Adam

The Safety Dance (With Apologies to Men Without Hats)


Things like this make me CRAZY:

She peered around the edge of the doorway.  Harry the Horse and Big Julie were huddled over the table, staring at the cards in their fists, blissfully unaware that death stood on the other side of the door jamb.  She took a moment, forcing herself to center, controlling her breathing, achieving an inner calm.  In a few moments, nerves and worry were gone, and all that remained was a cold, steely determination.  She reached back and curled her fingers around the butt of the Smith & Wesson Model 686 .357 Magnum revolver holstered behind her right hip.  With a practiced tug, she pulled it from the holster, flipped off the safety….

Grrrrr! <Said through gritted teeth> "Revolvers. Don’t. Have. Safeties."*

That’s usually the place where I put the book down and walk away or fight the temptation to run screaming from the  movie, frustrated by the lack of accuracy. Since I hate to walk away from a perfectly good book, a general discussion of the mechanical safety mechanisms found on handguns might be useful for those of you involved with writing books or producing movies.  Especially if you have curmudgeons like me in your audience.

Manual Safety on a Browning Hi-Power
Let’s be clear from the start:  An external, manual “safety,” or safety catch is a mechanical mechanism that is designed to reduce the likelihood of an unintentional or accidental discharge of a firearm.  It is usually a switch that, when engaged, prevents the firearm from discharging when the trigger is pulled.  Typically, the switch interposes a mechanical block that prevents either the trigger, the sear (the intermediary component acted upon by the trigger that holds and/or releases the firing mechanism) or the firing mechanism itself from moving.  Ideally, the safety must never interfere with the intentional discharge of the firearm.

Risky Business

Safeties are about managing risk and probability, not providing mechanical absolutes.  Mechanical devices can, and routinely do, fail.  Certainty can be achieved only by never loading the firearm.  Importantly, in cases where other functional attributes of the firearm manage the risk of unintentional discharge to an acceptable level, external/manual safeties are either redundant or omitted from the design entirely.

To understand safeties, it is necessary to understand what comprises the “risk condition” in a firearm.  This, in turn, requires a bit of knowledge as to how firearms and ammunition work.  

Bang for the Buck

Cartridge Components
Ammunition functions on the principle that the controlled burning of a given amount of solid propellant will cause the generation of rapidly expanding combustion gases, and that the expansion of these gases will force a projectile down the barrel and toward the target.  Reliable ignition of the propellant is ensured through the use of a chemical primer compound.  The primer compound is impact sensitive, meaning that it detonates when struck sharply, producing a short, intensely hot flame. (Think of the cap guns you had when you were a kid.)  It is this flame that ignites the propellant.



A (Spring) Loaded Question

Note firing pin and hammer
The role of the firearm’s firing mechanism is to consistently transfer kinetic energy to the primer compound.  Typically, this is done by causing a steel firing pin to strike the base of a cartridge, where the primer is located.  The motive energy that moves the steel pin is stored in a compressed spring (the “mainspring”).  The spring is held under compression by a mechanical block until it is released by the trigger to either act directly on the firing pin or to forcefully rotate a hammer, which strikes the firing pin, causing it to move rapidly forward.

These basic mechanics result in the existence of three distinct operating modes for a firearm:

  • Rest, when mainspring is relaxed and there is no energy stored to propel the firing pin;
  • Ready, when the mainspring is compressed, storing energy to propel the firing pin; and
  • Firing, the instant when the mainspring is released, expending energy and propelling the firing pin into the primer at the base of the cartridge.
Risk Model for Unintentional Discharge
Of the three, the risk space for unintentional discharge settles by a wide margin (some studies say as much as 9:1) in the Ready mode.

Safeties then, are a means of mitigating the risks attendant to having a compressed spring behind a firing mechanism that is restrained only by a controlled release mechanism (i.e., the trigger/sear).

Options

Safety on a Luger Pistol
The manual safety, like those found on a German P.08 Luger or an American M1911A1 pistol is one option to mitigate the risk of an unintentional discharge.  It is ideally suited for single action pistols where the Ready mode is a normal mode of carriage, where rapid employment not requiring manipulation of the breech mechanism is desired and where the pistol’s design precludes bringing it into operation without first manually compressing the mainspring.  

Colt Single Action Army.  No safety.
However, the manual safety is only one mitigation to the risk problem, and incidentally, not the first.  The original mitigation is found on single action revolvers like the Colt Single Action Army, was simply never to cock the pistol (and therefore compress the mainspring) unless it was desired to immediately bring the pistol into action.  This is a training mitigation (or, as those of us on the military end of the spectrum like to say a “tactics, techniques and procedures” (TTP) fix).  While it may not directly answer the mail, it does make for a mechanically simpler and therefore more robust design.

The most effective option, from a risk mitigation perspective, was to all but eliminate the need for a Ready mode.  If the trigger can be made to perform TWO functions; that is, both cocking the firing mechanism (compressing the mainspring) *AND* releasing the firing to hit the primer, there is no need to secure the firing mechanism against the force of the compressed mainspring.  Thus was born the double action pistol.

Double action S&W M60. No safety
On a double action pistol, the amount of force that needs to be applied to the trigger to overcome both the mainspring weight and the mechanical interplay of the fire control components is significant; between eleven and fifteen pounds of force is required to overcome the mechanical disadvantage and fire the pistol.  The possibility of this amount of force being applied accidentally is remote, and as a result there are almost no double action revolvers on the market today that have an external mechanical safety.  (As a note, most modern double action revolvers feature a number of internal, passive safety mechanisms intended to minimize the chances of a discharge should the firearm be inadvertently dropped.)

FN P45. That's a decocker, not a safety.
The lack of an external, manual safety is also a feature of modern double action semi-automatic pistols, for much the same reasons discussed with respect to revolvers.  However, double action semi-automatic pistols present a somewhat different risk mitigation challenge than double action revolvers.  Specifically, at the completion of a firing cycle that has not exhausted the ammunition supply, a double action revolver returns to the Rest mode.  A double action semi-automatic pistol on the other hand, returns to the Ready mode (Glocks and “Double Action Only” pistols are exceptions to this rule).  To allow the pistol to be safely returned to the Rest mode, many double action pistols have a decocking mechanism.  The decocker, while having the external appearance of a manual safety, performs an entirely different function.  It allows the mainspring to be safely decompressed without discharging the pistol.  As an aside some pistols, notably James Bond’s Walther PPK, combine the functions of safety and decocker in a single lever. (As a note, most modern double action pistols feature a number of internal, passive safety mechanisms intended to minimize the chances of a discharge should the firearm be inadvertently dropped.)
Walther PPK. Combined decocker and safety.

Conclusion

In sum, the manual external safety is a device intended to mitigate the risks attendant to carrying a cocked pistol with a round of ammunition ready.  The following is a quick cheat sheet that might be useful when arming your characters:

  • Single Action Revolvers (think “cowboy guns”): No external safety
  • Double Action Revolvers (think “police pistols from the 30s - 70s”):  No external safety
  • Single Action Semi-Automatic Pistols (think “GI .45s”):  External manual safety
  • Double Action Semi-Automatic Pistols (think modern military pistols):  External manual decocker
  • Glocks: No external safety
 *For every rule, there are, of course, exceptions.  The German Model 1879 Reichsrevolver, the Webley-Fosbery Automatic Revolver and the Mateba Model 6 Unica Autorevolver all have safeties.  They’re also rare, obsolete or a combination thereof.  Then there are folks in the “can’t let well enough alone club” like  Tarnhelm Supply, who are always seeking to gild the lily.