Vital small arms experience gained during the fighting of World War 1 (1914-1918) led global gunmakers to develop refined machine gun forms. A sub-category of the breed, born out of the war, became the "Light Machine Gun" (embodied by such types as the American Browning 'BAR') which brought with it portable machine-gun-like firepower at the infantry level. No longer would machine gun teams be restricted to simply defending positions but could now "take the fight to the enemy" alongside their riflemen counterparts. The trench-fighting experiences resulted in production of lighter and robust weapon systems that could better stand up to the abuses of wartime and, internally, the actions were made more reliable to better cope with the battlefield environment (and its inherent abuses).
In Finland during the mid-1920s, the Lahti-Saloranta M/26 (LS/26) was developed as such a weapon through joint-work completed by Aimo Lahti and Arvo Saloranta (as such the gun carried both of their surnames). Not only was the weapon developed with the Finnish Army in mind but also to those global parties looking to modernize their fighting forces in the post-World War 1 period. Work on the gun occurred in 1925-1930.
At its core, the weapon utilized a traditional rifle-like configuration with a solid wooden shoulder stock and pistol grip, metal rectangular receiver, and a perforated/jacketed barrel. A curved magazine was inserted into the magazine well ahead of the pistol grip/trigger unit in the usual way (the ejection port was set over the left side of the magazine). Under the barrel was affixed a folding bipod assembly and iron sights were provided for the shooter. The barrel was designed as a "quick-change" type to prevent fracturing from overheating - thought the bolt had to be removed during the change process (which could introduce all manner of debris into the action when reassembled). The machine gun weighed 20.5lb and had an overall length of 1,110mm, the barrel itself being 500mm long.
Internally a short-recoil-operated, rotating bolt action system was in play allowing for repeat fire - selection allowed for single-shot or full-automatic modes of fire. The chamber accepted the 7.62x53mmR rifle cartridge introduced by Finnish industry in 1918, this cartridge based in the original Russian 7.62x54mmR rifle round of 1891. The weapon could feed from a 20-round detachable box magazine or a 75-round drum (the "LS-26-31" model). In either case, rate-of-fire reached between 450 and 500 rounds-per-minute with the muzzle velocity was rated at 2,625 feet-per-second, effective range measuring out to 400 meters under ideal conditions.
The M/26 entered service with the Finnish Army in 1930 (following a competition dating back to 1925) and these served until the 1950s as a standard-issue weapon. However, the expected foreign market never developed due to the down-market brought on by The Great Depression (1929-1939) and the disruption that was World War 2 (1939-1945). The latter did allow the series to be in widespread circulation during the "Winter War" (1939-1940) between Finland and the invading Soviet Union and played a role in the follow-up "Continuation War" (1941-1944) as well as the "Lapland War" (1944-1945). In service, the guns were found to be cumbersome and internally complex though accuracy was a particularly strong quality mainly due to the inherently low rate-of-fire.
The weapon also managed to see fighting in the Second Sino-Japanese War (1937-1945) in the hands of Republic of China forces - though only about 1,200 or so of the 30,000 ordered (in 7.92x57mm Mauser rifle chambering) were actually delivered due to Japanese political interference (Japan was at war with China).
Total production (from 1927 to 1942) by Valtion Kivaaritehdas reached between 5,200 and 6,200 units.