In the BOCN downloads section: Kurze Beschreibung der Munition Fur Die 20mm Madsen Kanone Gegen Luftziele Und Tanks = Brief description of the ammunition for the 20mm Madsen Cannon against air targets and tanks.
A/S Dansk Rekylriffel Syndikat Compagnie Madsen Kopenhagen = A/S Danish Rifle Syndicate Company Madsen Kopenhagen.
No date but most likely pre WW2.
Five nice color plates (see one below) showing different types of 20mm Madsen Ammunition and projectiles. http://www.bocn.co.uk/vbforum/downloads.php?do=file&id=525
A/S Dansk Rekylriffel Syndikat Compagnie Madsen Kopenhagen = A/S Danish Rifle Syndicate Company Madsen Kopenhagen.
No date but most likely pre WW2.
Five nice color plates (see one below) showing different types of 20mm Madsen Ammunition and projectiles. http://www.bocn.co.uk/vbforum/downloads.php?do=file&id=525