Hollow Point or Incendiary Bullet? You decide
By Gregory Kielma
Why explosive rifle bullets don’t explode in barrel when fired? Bullet is under stress, heated, deformed while traveling through barrel, acceleration is extreme. So how do these actually work without detonating in barrel?
Why explosive rifle bullets don’t explode in barrel when fired? Bullet is under stress, heated, deformed while traveling through barrel, acceleration is extreme. So how do these actually work without detonating in barrel?
Gregg Kielma
There are very few purposely designed “explosive” bullets as there was no real need for them in warfare as being hit with a rifle bullet travelling more than 2400 fps is more than adequate to cause a casualty.
However, one bullet design, which was meant for pilots to help visually track their MG fire was secretly adopted by Germany and Russia for use by snipers to create fear in their enemies.
It was not a true exploding bullet, but it contained white phosphorus which could be mechanically ignited if it hit and deformed on a target. In the photos below, the bullet would retain integrity when handled and fired, but upon striking something, deformation of the tip would drive a copper cap filled with WP into the internal needle and the friction would cause ignition. The rapid ignition and expansion of the WP did cause an explosive effect in humans.
I don't know if this was used, but the Japanese did design a true explosive bullet, where explosives were set inside the ballistic tip. As the tip was narrower than the body of the bullet, it did not engage with the rifling when fired, so was not subjected to the same compression forces that would have likely detonated it during firing.
A modern design for a multi-function HE, HEI, AP, API, APHEI round called the “Raufoss”, was designed for .50 BMG bullets using very stable materials such as PETN, and which is drop-safe from 15+ meters. However, when the bullet strikes a target, the tungsten penetrator is driven forward more than 4,000fps and ignites the zirconium like a match. This causes both detonation of the explosive and ignition of the incendiary in the tip.
So now you know!