Ki-43's shot down B-17's and B-24's not to mention tough fighters like the P-47 with just two .303's, I bet the RAF pilots would have loved to have replaced their eight British made .303's for two of the Japanese models!!!! Being serious planes from the start of the war to the finish flew home with holes all over them from battle, you only have to look at gun camera footage to see aircraft riddled with fire from all calibers yet break away and escape but only the BoB experience is ever discussed.Which 50 cal? In 1940 it wasnt what it became in 1943/4. They cause different damage. In 1940 RAF pilots were being struck and damaged by single rounds from 20mm cannon while seeing German bombers sail through hundreds of hits by their 0.303 mgs. Post war it was found that although many bombers didnt go down straight away, they ditched or made forced landings with dead or injured crews, by mid September 1940 what was th most formidable airforce in the world was down to its last 200 serviceable bombers and crews.
A Hurricane that was hit with cannon fire tangling with 109's over France yet returned to base