Staff Writer (Updated: 5/16/2016):
The gun was chambered for the .30-06 Springfield cartridge and the rounds were fed through a 25-round detachable box magazine inserted into the left side of the receiver. The magazines were a single stack arrangement which promoted a very slim, though lengthy, profile. Additionally, the weapon supported reloading via single cartridges or the American standard five-round clip (charger) from the right side of the receiver with the box magazine in place. This feature was born from the military requirement to have the LMG be belt-fed.
Overall weight was 13lbs with an overall length of 42 inches and a barrel measuring 22 inches long. Rate-of-fire was adjustable by way of managing the tension of the buffer spring - between 200 and 900 rounds per minute being theoretically possible. The short-recoil method of operation made the Johnson LMG one of the few light machine guns to actually use this action in its design. The machine gun also incorporated single-shot and full-automatic fire functionality which used a closed bolt and open bolt operation, respectively.
By 1940, the design was more or less finalized and production began that same year while spanning into 1945 - the final year of World War 2. However, the guns were manufactured to a high standard which meant that it made a rather poor choice for wartime serial production where expediency in stocking inventories was key. The United States Marine Corps (USMC) trialled the weapon, but this exercise did not lead to formal adoption of the system and this left the weapon to the foreign market to which the Dutch placed the only notable order. The Johnson LMG was intended to stock the Netherlands East Army in response to encroaching actions by the Japanese Empire nearby. However, the Japanese advanced on Dutch territory and future orders were cancelled since their arrival would come too late to be useful. It was only through limited use by Army Rangers and other special operative groups during the war that the Johnson LMG persevered to the end of the conflict (and in production). It also saw service with the Philippine Army during the Japanese occupation of the country and with select forces of Canada and the United Kingdom.
At its core, the Johnson Model 1941 was a functional, though complicated and expensive, portable machine gun designed to provide the infantryman with a less cumbersome alternative to the World War 1-era M1918 Browning Automatic Rifle (BAR) while retaining all the usefulness of the .30-06 cartridge it employed. Some reports noted weak design (leading to breakages) and regular jamming of the action when the weapon was pushed under battlefield conditions. The primary production model was the M1941 which was identified by its wooden buttstock as well as a folding bipod held under the fore-end. The alternative model became the M1944 which brought along a twin-tube shoulder stock (replacing the wood one) and a cylindrical monopod (taking the place of the original bipod).
What examples of the Johnson LMG that remained in circulation after the Japanese surrender stayed in action into the 1960s.