Lots of talk on the internet and media about the Norwegian killer using “exploding bullets.” I’m going to bet this is not the case, and this is an instance of Norwegian doctors not having a lot of experience treating gunshot wounds. Most rifle rounds are going to fragment and cause horrific wound channels.
The term dum dum bullet is somewhat antiquated, and to use it to describe modern JHP ammunition is not really correct. The name comes from the Dum Dum arsenal, near Calcutta in British India, where they were invented. Their inventor was Neville Bertie-Clay. The bullet he invented is today what we would call a soft tip, or soft point, which is now commonly used in hunting, but rarely used for police or civilian self-defense rounds.
It’s been disheartening but not surprising watching how ignorantly the press is misconstruing what “Dum Dum” bullets actually are. They are, essentially, common hunting rounds. They do not explode inside the body. Rifle rounds, traveling typical speeds of about mach 2.5 to mach 3, generate enough energy to cause horrific wounds in their own right. That’s why they are used in hunting.