For all practical purposes this rifle can be described as re-barreled and slightly improved version of M/91 infantry rifle made for Suojeluskunta (Finnish Civil Guard). In early 1920's Suojeluskunta made alarming observation that over large amount of about 70,000 M/91 rifles in its use had seriously worn barrels, which were in hardly in usable shape any more. At the time Finland had no industrial plants, which would have manufactured rifle barrels before. SAT (= Suomen ampumatarviketehdas = Finnish Ammunition Factory) had manufactured small experimental production series of M/91 rifle-barrels around 1919 - 1920, but with poor success. Also Tikkakoski factory did not start making rifle barrels until year 1925. Suojeluskunta ordered 3,000 rifle barrels from Swiss factory S.I.G. (Schweitzerische Industrie-Gesellschaft, Neuhausen) in April of 1923. Next year 5,000 rifle barrels were ordered from S.I.G. - these 5,000 rifle barrels were apparently already thicker stepped version. A separate order for M/91-24 rifle barrels was sent to consortium of German manufacturers, which delivered another 5,000 rifle barrels marked with Böhler Stahl in May of 1924. What is known now these Böhler Stahl marked barrels were also apparently of thicker stepped version. Replacement work of the old rifle barrels with new ones started as soon the new rifle barrels started arriving to Finland.
The first 13,000 barrels Suojeluskunta acquired from S.I.G and Venus Waffenfabrik all had the same (thickness) dimensions as Russian original ones (used in original M/91 infantry rifle). But then the idea of using thicker rifle barrels to improve accuracy has already gained popularity. June 1925 drawings for a new 1.5-mm thicker rifle barrel were completed. By March of 1927 Civil Guard bought another 13,000 of these thicker rifle barrels for M/91-24 rifles from German Venus Waffenfabrik, which delivered 8,000 of them in August of 1925 and 5,000 in November of 1926. Suojeluskuntien Asepaja (= Gun smith shop of Civil Guard, it later developed to SAKO) took care of installing these new barrels between August of 1925 and early 1928. During this time rifle barrels of almost 26,000 rifles were replaced with these new barrels. While earlier information suggested that half of M/91-24 rifles were with old M/91 barrel profile and another half with thicker stepped barrel, this page now reflects new information gathered from remaining rifles. That new information suggests that only the first 3,000 rifle barrels ordered from S.I.G. were with original M/91 infantry rifle barrel profile and 23,000 rifles were equipped with thicker stepped rifle barrels. Starting from May 1926 rifles getting a barrel replacement started receiving also few other improvements done along replacing the barrel. These improvements included:
-Trigger mechanism was checked and new sensitivity ("mousetrap") spring installed, after this trigger pressure was adjusted.
-Sights were improved. Measurements in meters were marked to rear sight. -New L-shaped aperture blade attached to rear sight provided better sight picture. Also a new front sight was installed, but design-wise was similar to one used in rifle M/91.
-Rifle stock was modified to accept new thicker barrel by widening and deepening the barrel channel. These rifles were quipped with either one-part rifle stock used recycled from infantry rifle M/91 or with a new rifle stock, which was two-part design with its parts attached to each other with finger joint. Also handguard was modified accordingly.
As part of the process each rifle was also totally cleaned and all broken parts repaired or replaced. The improvements introduced with M/91-24 were included also to later designed M/28 and M/28-30 rifles of Finnish Civil Guard. For example sensitivity spring (so called "mouse-trap spring" introduced with this rifle remained unique characteristic of Civil Guard rifles and was used in all later Mosin-Nagant rifles issued by Civil Guard. Barrels of later M/28 and M/28-30 were thicker than in original M/91 or M/27 of Finnish Armed Forces. Sights however didn't remain the same - further improvements to them were introduced with M/28 and M/28-30 rifles.
Finnish nation-wide voluntary defence auxiliary organisation Lotta-Svärd was a large financier for the purchases of rifle barrels for these rifles (at year 1923 Lotta-Svärd organisation had collected sum of 545,337 Finnish Marks in donations for this purpose). So the rifle got nick-named as "Lotta-rifle". Year 1928, just after M/91-24 rifle project had ended, Suojeluskunta had almost 25,000 M/91-24 rifles in use. Starting from year 1935 Suojeluskunta members could send M/91-24 rifle issued to them to be replaced with M/28-30 rifle if they paid most of the expenses. Because of this the number of M/91-24 rifles started slow but sure decline. The amount of M/91-24 rifles was bit under 22,000 in May of 1936 and decreased to 19,400 by May of 1939. To simplify repairs during World War 2 Finnish military included M/91-24 rifles into same spare part category with M/91 infantry rifles, because of this during repairs many of M/91-24 received replacement parts made for M/91 rifles and in this way they lost some of their own characteristics. When Finnish Civil Guard was disbanded after World War 2 remaining M/91-24 rifles were given to Finnish Armed Forces and later they were sold (mostly abroad) simultaneously with M/91 infantry rifles.