One downside to this is that the deforming lead is more likely to fragment and remain in the target, in small pieces. Hunters would use them to bring down large game that might otherwise go berserk and run off (or worse, towards the hunter) wounded, if hit with a penetrating projectile. They increase the chance of doing lethal damage with a single hit. They are enormously effective at increasing the lethality of high-velocity, smaller caliber rounds - bullets fired from long ranges, at high speeds, etc.

These bullets are of reduced effectiveness against body armor since the way modern ballistic armor works is to attempt to spread the force of a bullet's impact rather than allowing it to penetrate, they play to its strengths. Technically, the true 'dum dum' is a soft-nosed projectile - one in which the metal jacket material of the bullet stops short of the bullet's tip, leaving the soft lead exposed. The purpose is the same - to ensure that when the bullet strikes an object, it will flatten or 'mushroom' and hence transfer more kinetic energy to the target material rather than blasting a hole through it. There are various means by which a bullet can be designed to do this - hollow point, soft point (also known as soft nose) or cross cut. Unfortunately, there is no 'official' technical definition of a dum-dum, but the purpose, function and history of the bullet can be gleaned from research.ДЄ 'dum dum' bullet is a slang term indicating a type of bullet designed to impart greater stopping power to its target by deforming on impact. The term 'dum-dum bullet' is used as slang to describe a variety of bullet types.

Dum dum bullets