Why Did Spitfires Change Their Guns?

This is one of Imperial War Museums' most prized possessions. A genuine, airworthy, combat-veteran Spitfire Mk 1. Early Spitfires were initially equipped with eight machine guns. They fired the 303-rifle calibre machine gun round. But much like the Spitfire through its development, not only did it gain things like bigger engines, but also a larger armament. In the case of the 20mm cannon and the .5-inch machine gun.

The story of the Spitfire's armament development is complicated and can even be considered controversial to this day. To help us tell that story we've brought in Jonathan Ferguson of Royal Armouries who's going to help us take an in-depth look at the main weapons of the Spitfire.