My source handed me over these two cases together. It seems they are british, at least according one headstamp (K4 Kynoch). But what with the ‘H’ case? Winchester? Both are berdan-primed and it looks the cases had a black coating. Case-lenght is approximately 110 mm. According my source, it should be aircraft-ammunition which seems presumable as the Mosquito and Spitfire Mk IX, both with 20 mm cannons, were very common in the Flemish skies, summer of 1944. So far the story. What about the facts? Anybody?
Yes, British 20mm Hispano casings (20x110mm), and possibly fired from British aircraft during WW2.
K4 - I.C.I. (Kynoch) Yeading, Middx and H is Hall’s Telegraph Co.
Both cases are dated 1944.
The remnants of a black coating is probably the result of something that happened to the casings after being fired since coating these types of cartridge casings with something (i.e. paint) prior to use was not standard procedure and would have mostly likely caused the guns to jam. Not something you want to have happen, and definitely not while flying over enemy held territory.
From the looks of the “crimp” on the mouth and the vestiges of black paint, I’d say the case was used for something in later life, perhaps a souvenir or decoration of some kind?