MIKHAIL KALASHNIKOV died on December 23rd, aged 94. But his 66-year-old invention, the Avtomat Kalashnikova, has plenty more shots left to fire. Developed in 1947 and first used by Soviet forces in 1949, the AK-47 assault rifle and its many derivatives are now used by the armed forces of more than 80 countries, and by freelancers in many more. No-one knows quite how many are in circulation: 100m is a reasonable guess. As a proportion of all the guns in the world—another number no-one can be quite sure about—Kalashnikovs probably make up more than one in ten of all firearms. Why does an ageing Soviet invention still dominate modern warfare?

The cultural impact of the AK is felt all over the world. Quentin Tarantino’s villains celebrate its appropriateness for “when you've absolutely, positively got to kill every [enemy combatant] in the room”. Mexican outlaws boast about their cuernos de chivo, or “goat horns”, the nickname given to the rifle because of its curved magazine. In some parts of Africa, where the gun is seen as a symbol of the ousting of colonial rulers, Kalash is a popular name for boys. Mozambique displays the gun on its flag. In Lebanon, a model nicknamed the “Bin Laden” sells for twice the price of the standard AK-47, because it is the type that al-Qaeda’s former boss was seen toting in some of his videos.

The gun is nothing special. Its controls are unsophisticated; it is not even particularly accurate. But this simplicity is a reason for its success. Compared with other assault rifles, the AK-47 has generous clearance between its moving parts. That is bad for accuracy, but it means that the mechanism is unlikely to jam, no matter how clogged it gets with Sudanese sand or Nicaraguan mud. Designed to be operated by Soviet soldiers wearing thick winter gloves, it is simple enough for untrained recruits (including children) to use. These features explain why the gun has remained in demand. But its success is also down to supply. The Soviet Union wanted to standardise military equipment among its allies, and so shipped giant caches of the weapons to friendly states, where it also established factories to churn out the rifles by the hundreds of thousand. (The USSR was unconcerned with copyright, too, meaning that knock-offs proliferated.) The gun has spread all over the world. But where the Soviet Union had less influence, the AK-47 was less popular. To this day, bandits in the Philippines are more likely to use variants on the M16, an American-made assault rifle supplied to the Philippine army by the United States.

With the AK’s dominance firmly established, it has proved hard to displace. In Syria, some fighters were pictured using FAL assault rifles, which by some accounts are superior. But they didn’t last long because it proved hard to find ammunition: the FAL takes 51mm-long cartridges, which are thinner on the ground in conflict zones than the 39mm-long cartridges used in the older types of AK-47, according to Nicolas Florquin of the Small Arms Survey, a Swiss research-organisation. Perhaps most fundamentally, the basics of warfare haven’t changed all that much since the second world war. Drones and smart weapons are revolutionising rich-world armies. But elsewhere, much of today's bloodletting follows a similar pattern to that seen in the 1940s. Until warfare evolves, the AK-47 will remain as devastatingly useful as it was half a century ago.