It's a 93 action. Ludwig Loewe / DWM made M93 actions were also used by Suhl gunmakers in making the famous 7x57 "Plezier Mausers" at the time of the Second Boer War, 1899 – 1902. The M93 action was a quite modern action then. So I tend to fate the rifle to the first years of the 20th century, 1900 - 1905. The scope mounts were added later, most likely in the 1920s - 30s.
Rifle bore dimensions were not standardized before 1926. Each barrelmaker bored and rifled his barrels to the dimensions he felt to be best for the cartridge intended. In older civilian barrels you often find differences in bore size, groove numbers, depth and shapes.