Voronezh Governorate
Mosin was born in Ramon, in the Voronezh Governorate of the Russian Empire in 1849. He entered into a military academy at age 12 where he excelled as a young officer. In 1867, he entered the Alexandrovskoye Military High School in Moscow. Upon leaving Alexandrovskoye in 1870, he decided to go to the artillery branch and transferred to the Mikhailovskoye Artillery Academy. He graduated in 1875 and transferred to the Tula Arsenal where he became the head of the machining division.