Bullet design has changed over the ages, progressing from a round ball of lead to the modern monolithic copper rifle projectiles of today. During those years there has been many developments in bullet design, some of them are more trick than practical treat. Because of the Hague convention modern military organizations rely on fully jacketed bullets that do not expand and are considered less than lethal. The idea is to wound an enemy and tie two or three others up getting him off the field. Of course, that only works if the enemy does stop to render aid, but most of our adversaries have been less able or have the proclivity to do so until after the engagement.
Dum Dum Arsenal & Expanding Projectiles
The original expanding projectile used by a military where made in the Dum Dum arsenal in British Colonial India, hence the term Dum Dum bullet. Hague convention prohibited expanding ammunition from use in combat. Though the US never signed the accords, our ammunition has since complied with this requirement. But the Soviets and British had a work around. They designed the bullet to tumble on entering the body, increasing the damage and wound effect. Even highly stabilized bullets will destabilize, and tumble given enough distance through a denser media. The problem encountered in the middle east conflicts is that the malnourished enemy is so thin that the bullets from the 5.56mm NATO pass through without stabilizing, requiring more hits to stop an aggressive action of the enemy. The Hague Convention prohibits the use of expanding ammunition between signees of the accord and against uniformed military personnel. In insurgent or guerrilla warfare you can technically use what you want. That is why using expanding bullets by individuals, hunters and law enforcement is ok. The goal is to neutralize aggressive armed behavior as quickly as possible to preserve life and limb of the victim and surrounding innocent bystanders. The goal is neutralization and not to kill. However, the neutralization of aggressive behavior involves damage to the vital organs and to the central nervous system.
Expanding Handgun Bullets
The most effective tools are expanding handgun bullets. When the bullets strike, they open a wound channel and transfer energy to the target. The permanent cavity is smaller than the temporary cavity. As the bullet passes through a target the kinetic energy is transferred to the target media, muscle, organs and nervous system. The larger the temporary cavity more energy is transferred to the target. By designing the bullet to expand this transfers more energy in a short time leading to more tissue damage. Organs like the heart and lungs penetrated by a project help to debilitate the enemy. Severance of nerves can lead to immediate cessation of the aggressive action. Bullets, unlike an arrow, don’t cut through tissue. Bullets crush and tear their way, and as the expanded bullet increases in size so does the volume of the permanent cavity, after the collapse of the temporary one. The expanded bullet augmented the size and effect of this permanent cavity. As an aside an arrow kills by cutting through arteries and veins to bleed out the target. Its like being stabbed from a distance. That is why the modern broadhead arrow type is used by hunters. It is essentially razorblades on a stick.
Mercury and garlic bullets are more myth than effective projectiles. Use of either can get you in more trouble than standard expanding ammunition. According to lore the gangsters of the ‘30s used bullet rubbed in garlic to cause poisoning and infection. Mercury in a hollow point sealed with wax was supposed to make the bullet explode. None worked as advertised and if used could influence the courts to turn a righteous self defense scenario into a manslaughter conviction. Use of handloads is also controversial, one is best served to use the best factory ammunition available.