The basic equipment of the Finnish Army came from what was left in Finland by departing Russian soldiers when Finland declared independence. As the Russians had no scoped rifles at that time, Finland didn’t have any either. The Finnish Army began experimenting slowly with the concept of a scoped military sniper in the 1920s, but really didn’t do anything. The Civil Guard made a few dozen experimental snipers in the 1920s and 30s, but also nothing of real significance.
In 1936, the Army finally made a concrete move, contracting to purchase 250 3x optical sights from Physica Oy in Helsinki. These were intended to be universal optics, suited for mounting on sniper rifles, machine guns, and small cannon – an idea that looks great on paper but is actually terrible. By the time the Winter War began, only 84 of the scopes had been received. Ultimately, 150 of the scopes were assembled onto M27 pattern sniper rifles, with the remaining 100 scopes put into storage (none would ever actually be used on machine guns or cannon). The scope had a number of problems; it was heavy, awkward to use, had very short eye relief, and tended to fog up in cold weather.
When the Continuation War began, the M39 had replaced the M27 as the standard Army rifle. The M27 PH snipers were mostly torn down, and the scopes were mostly used to assemble new M39 PH rifles. These had largely the same problems that the M27s had, and they were not particularly popular arms during the war.
In addition to the M39 PH, Finland also built a number of M39 SOV snipers using capture PE and PEM Russian scopes, a few hundred M39-43 snipers with German Ajack 4x scopes, and a few hundred M39-44 snipers with a domestic Finnish copy of the Ajack. None would be of real significance during World War Two, with the M39-44s not even completed until after the war was over for Finland.