Mosin case manufacturer

I have this one from 1913 without manufacturer; stamped 13 III. I heared that they were produced in Sankt Petersburg in 1905 -1913. Anybody know exact manufacturer or have sources about this?

History of production and marking of rifle cartridges 7.62x54R for the Mosin rifle.


“Roman numerals indicate the period (4 months) of manufacture of the cartridge - i.e. I, II or III third of the year. The word “trimester”, often used to decipher this designation, is not suitable, because means “three-month” and is equivalent to the term “quarter”.
In 1907-1913, cartridges without manufacturer markings were produced. The location of the protruding markings on them is similar to the labeling of products of the St. Petersburg plant, which is most likely their manufacturer.”
Example drawing from the above source-85


Thank you!