But what's this Dum-Dum business? What really makes a dum-dum bullet different from/worse than other bullets?
Warning: this is the dumbed down version (pun not really intended). I made the mistake of asking the resident shooters licence holder (RSLH) for an explanation of the different bullet types & got pointed at various books with pictures of bullets and guns and lists with numbers - lots of numbers – denoting calibre, muzzle velocity, bullet weight, muzzle energy... So I asked for the shorthand version, which got me a "you must be kidding me" look, but some useful info as well. I'm just sayin' this is likely very incomplete *g*. With that in mind, on we go…
A "Dum-dum" is most accurately the name given to a type of bullet manufactured in about the late 1890's at Dum-Dum Arsenal in North-West India. The bullet, made for a .303 calibre gun, had an incomplete metal jacket. The nose of the bullet was left bare, exposing the soft lead core, meaning the bullet would flatten on impact, doing more damage as a result. The base was also bare, which sometimes meant the jacket got left behind in the barrel – highly undesirable!
[Bear this in mind: early guns fired lead balls, which naturally expanded on impact, unrestricted by jacketing. As guns developed, so too did the ammunition. Lead bullets shot at high(er) velocities fouled rifled gun barrels, so metal jackets came to be used. Metal-jacketed bullets didn't expand and were less likely to do enough tissue damage to deliver a fatal or incapacitating knock-down blow to an enemy. Hence the development of soft and hollow-pointed bullets, particularly for use by colonial troops against larger numbers of native insurgents who might otherwise over-run European troop positions]
Because of the problems with the Dum Dum bullets the British went on to manufacture their own, the Mark III and the Mark IV. Also, soldiers given fully jacketed bullets occasionally 'doctored' them by removing the metal around the nose.
Eventually objections were raised (by the Germans, in case the English used the bullets against them rather than against anyone else in Other Parts of the world), and The Hague Convention of 1899 came into being. The Declaration on the Use of Bullets Which Expand or Flatten Easily in the Human Body states:
The Contracting Parties agree to abstain from the use of bullets which expand or flatten easily in the human body, such as bullets with a hard envelope which does not entirely cover the core, or is pierced with incisions.
The present Declaration is only binding for the Contracting Powers in the case of a war between two or more of them.
It shall cease to be binding from the time when, in a war between the Contracting Parties, one of the belligerents is joined by a non-Contracting Power.
I can't find a list of signatories, however I understand that they included Britain and Germany. I have read in a couple of places that the United States has never signed. Anyway, by this time "dum-dum" was the commonly used term for all sorts of soft and hollow-nosed bullets.
OK – important point No. 1:- the Hague (not Geneva) Convention outlawed use of expanding bullets between combatant forces only where both are signatories. That's it. There is no such internationally recognised restriction on use of these bullets for other purposes, such as hunting or police use, or between non-signatory states.
Soft and hollow-nosed bullets are used by hunters because of their "stopping power", particularly when hunting big game (moose, anyone?). The best make of bullet to use varies depending on the type of game hunted. There are books and books on the subject, so, moving right along…
Some police forces use heavy calibre hollow-nosed ammunition for similar reasons – to stop armed perpetrators in their tracks and prevent officer or civilian casualties. Also, there are a couple of dangers with modern powerful handguns – ricochet and over-penetration – that are reduced with a bullet that's pretty much guaranteed to stay within the body.
Important point No. 2:- look at modern ammunition. A full metal-jacketed round might also be one that is designed, through weighting or other manufacturing variations, to 'tumble' or 'yaw' in the body, and/or fragment. In other words, to make a mess of living tissue in order to kill or incapacitate. RSLH says the jacketed rounds used for the M16 assault rifle in the 60's were sometimes known as "tumbling terrors" – they were lightweight, high velocity rounds that could ricochet within a victim's body, creating a significantly increased level of damage. Also, today's standard NATO issue rounds are designed to yaw and fragment on impact. Neither of these examples are Dum-Dums (they also relate to rifles rather than handguns fwiw).
If you like formulas the RSLH reminded me of an article he wrote for our re-enactment magazine that described a formula used by big game hunters at the start of the last century. It's called the Taylor Knock Out Formula (TKO Formula) and it works like this:
TKO = P.Wt x Calibre x M.V.
Where P.Wt - projectile weight (in grains)
Calibre = projectile diameter (inches)
M.V = Muzzle Velocity (feet per second)
7000 = a convenient number, there being 7000 grains in one pound weight.
The Formula was designed to use with non-jacketed hunting rounds, but it works in other situations pretty well. For example, the Browning Hi-Power used in seasons 1 & 2 had a TKO factor of 6.83, the .357 calibre revolvers they started using from 1979, using Magnum ammunition, had a TKO of 11.8 – almost double that of the Browning. But compare that to a 17th century matchlock musket that has a TKO of over 30! That's clearly not the whole story, after all the formula makes no distinction between a soft nose 9mm bullet and a jacketed one, but it does say something about the ammunition's "potential" when the bullet leaves the muzzle.
And finally, I know one of the things I wondered when I started thinking about this was whether CI5 would ever use expanding bullets, and I was halfway convinced that they would, despite Cowley's obvious distaste for them, due to the "stopping factor". But apparently partially jacketed ammunition is overall less accurate, and the RSLH thinks the Brits would go for accuracy rather than knockdown potential. Well, it fits. Not sure what the armed police units did then or do now & I'd be interested to find out. But as the man said, and kindkit pointed out in her 'Mixed Doubles' review, Dum Dums are "Just another way of killing."
ADDED: - The reference list:
Connolly, Sean (ed), Encyclopedia of Rifles & Handguns,1996, New Burlington Books, London,England.
Dockery, Kevin, The Armory Volume 1,1983, Firebird Ltd, Ann Arbor, MI, USA
Soft point bullet
Hollow Point Bullet
Full Metal Jacket Bullet
Rules of War and Arms control
An interesting field test – modified DumDums
A list of ammunition types for the .357 Magnum
The Internet Movie Firearms Database (imfdb) has a very good entry on "The Professionals".
Edited It finally dawned on me that "magnum" referred to the ammunition, not the gun. So I've slightly tweaked that section. 19 Jan 09.