DIS produced various mounts to Madsen. This is an early and really nice example of sales material from DIS.
Blog post on Mount N5 here
This is a two page pamphlet/brochure from 1936 printed on glossy paper by J. D. Qvist & Company in Copenhagen. Notice the modern font and the name indicating that the brochure is later than January 1936.
How the gun operated is described in a report from a demonstration of Madsen 20mm anti-tank and anti-aircraft gun, 1940
“The gun itself is a recoil-operated, magazine fed, pivot block type, which fires either fully or semi-automatic. Rounds are chambered by a rammer which operates on cam action during the cycle of the gun. The block is pivoted at its rear end to the barrel extension and during recoil a lug on the right side of the block, acting on cam surfaces in the receiver, raises the forward end of the block to clear the barrel breech and permit ejection. At the end of the recoil the forward end of the block drops below the breech, bringing a curved surface on its left side into alignment with the next round to be fed. The cartridge is forced against this surface by the magazine follower and as counter-recoil begins, the rammer pushes it forward and into the chamber. During the last few millimeters of counter-recoil the block is raised by cam action and brought to the closed position.
This type of block action requires that there be a large headspace in order that the face of the block will clear bhe breech as it pivots. Accordingly the cartridge cases have a thick rim and head to withstand the pressures on the unsupported part of the case.”
N4 Light Field Mount
The 20 mm Madsen had several mount options, from these the ground-support version with one axle and rubber tires was the most suitable one for antitank use.
Below is a detail from the picture of N4 Light Field Mount. The drum magazines kept in wicker boxes can be seen below.
F5 light Field Mount
A low slung tripod mount with recoil-absorbing mechanism. For transporting the gun on this mount, wheels are attached to the mount to make it easy for the gun crew to drag.
This mount could be folded (wheels removed) and stowed on the sidecar of a motorcycle for long distance transport over roads. The gun would be mounted in the gap between the bike and the box. Wheels were stored on the sidecar. The gun could be fired from the motorcycle mounting, although it is not adequately stable for accurate firing in this position.
In 1936 attempts were made to sell Nimbus outfits, in combination with the ‘System Madsen’ weapons, to Chiang Kai-Chek forces in China and to the Brazilian military. Both attempts failed, but in 1940, 100 army green Nimbuses were bought by Yugoslavia
(http://www.armyvehicles.dk/nimbusmc.htm). We are trying to investigating if any were delivered to Yugoslavia/Croatia.
As seen below, danish soldiers used the Danish military Nimbus motorbike with side car, mounted with 20 mm Madsen machine cannon. The picture is from 1940, before the German invasion.
F7 Universal Mount
The universal mount F7 permitted both anti-tank and anti-aircraft fire. It has a recoil-absorbing mechanism similar to the ligth field mount F5. The gun is fixed to the mount by fitting it to the recoil mechanism which is pivoted to the cradle of the mount, and the cradle, in turn, pivots on the body of the mount. Here it is seen in anti-tank position.
The mount is readied for travelling by folding the three outriggers, attaching wheels, and locking the gun in position.
F4 Universal Mount
The universal mount F4 M 1933 permitted both anti-tank and anti-aircraft fire. The mount permitted a 360 degrees Rotation and the gun could be tilted from a 5° to a 85° angle.
Here it is seen in anti-tank position
The F.6 mount for machine cannon will be the topic of the next blog post.