Interesting Cartridges



The  1135 mm  Madsen  Cartridge

 This “in between” machine gun cartridge enjoyed only limited popularity, and as far as is known to your Journal editor was loaded by only three countries – Denmark (the country of origin), the UK and Argentina.

The famous Danish company Dansk Industrie Syndicat AS 'Madsen', usually referred simply as Madsen, manufactured various weapons since the early 1900s.The MADSEN 20x120 Cartridge

The first Madsen machine gun for sale was produced in Denmark by the Dansk Industri Syndikat in 1904 and the last in 1950.  The Madsen, at its introduction, was one of the very first light machine guns and featured an overhead box magazine.  All models had a similar look and were produced in a wide variety of calibres and sold to over 30 different countries.  The peculiar action of the Madsen was best sited to rimless rounds.  A recoiling barrel activated a complicated, precisely machined plate plus associated bits and pieces, to open a Martini type action, downwardly eject the empty cartridge, load a fresh round and close the action.

[During WWII, it had become necessary to develop locally produced sub-machine guns. Australia developed the Austen Mk1 and Owen SMGs, the Italians developed the Beretta 38A, and the Danes developed the Madsen. The only exception would be the Japanese, who did not produce or use a submachine gun in any significant numbers, though they had purchased a small number of Swiss-made MP28/II SMGs before WWII began.

Soon after the war Madsen produced a 9mm  m/46 submachine gun, which was one of the last wood-stocked SMG's to be produced. In 1949 Madsen introduced a more modern design, the m/49, which featured an entirely stamped receiver, integral with pistol grip and magazine housing.

The Madsen SMG was not commercially successful post-WWII due to the large number of surplus SMG's which had flooded the market.

This SMG also featured unusual charging handle, a bracket-shaped slider above the receiver. But the most unusual feature of the m/49 was the field stripping procedure. The receiver was made from two halves, left and right, hinged at the rear, and held together at the front by the screw-on barrel nut. To disassemble the gun, one must unscrew the barrel nut, and then open the left side of the receiver/housing. Barrel, bolt, return spring and trigger unit will remain in the right "half" of the gun, easily accessible. The hollow pistol grip contained magazine loading tool, and there wee no manual safeties; instead, Madsen m/49 had an automatic safety in the form of the lever just behind the magazine housing; to fire the gun, one must grasp the magazine and this lever securely by non-firing hand, to be able to release the bolt. Otherwise, the m/49 was a fairy conventional blowback design, which fired only in full auto.

Next year Madsen introduced the M/50, a slightly modified M/49 with more conventional and comfortable charging handle at the top of the gun, and in 1953 Madsen introduced the last gun in this line, M/53, which differed mostly in that it used a curved magazines instead of straight ones, and can be fitted with optional barrel shroud, which had a bayonet mount lug. Madsen SMG's were sold to various Asian and South American countries. Brazil makes licensed copy of Madsen in .45ACP caliber

The "peculiar" action of the Madsen was indeed that. A bullet never starts perfectly straight from the cartridge case as there is always a clearance between a cartridge and chamber, and the bullet's base is never perfectly symmetrical, when pushed through the crimp of case mouth. Every bullet thus emerges the muzzle with some yaw, known as "nutation" in Latin. Nutation is a rapid movement with a rate equal with a rotational rate gained from the bore rifling twist. Precession is a considerably slower yaw with more prominent amplitude. It is able to cause a spiral "corkscrew trajectory", often seen when shooting tracer bullets from a rifle with a faulty muzzle (and from a Madsen light machine gun, notwithstanding its perfect muzzle. The action of Madsen (see drawing beside) bends the bullets of its cartridges slightly askew before discharge. Therefore it was a very lethal "mowing machine" and it was produced over a longer period than any other light machine gun(1904 until late 1950s or early 60s, despite it's high cost price).

Some said that the Madsen bullet's precession in a random direction and rate diminished its accuracy so badly that it was almost impossible to hit a chart at 50 meters or the broad side of a barn at 100 meters. However, the precession produced by Madsen action was predictable -- its direction and rate were the similar and consistent, shot-after-shot. It's accuracy at known range was satisfactory, despite the "corkscrew trajectory" - WebEd]

In any case the 1135 x 62 cartridge was developed in the 1930’s, and guns and cartridges sold to Argentina.  The flat based 305 grain 465 calibre bullet had a mv of 2785 f/s.

 Doubtless, some Madsen guns chambered for readily available ammunition are still in  use somewhere in the world today.  I think though, the 1135 round and guns would be in honourable retirement.