The soldiers of Switzerland's conscript army apparently forgot them in different carriages of Swiss Federal Railway (SBB) trains, according to an article in ASMZ, a review for Swiss army officers.
The finding was acknowledged by Christophe Schalbetter, interim commander of the military police in his annual report.
Soldiers frequently travel by train for their training stints, carrying their equipment, including an assault rifle and pistol.
Politicians were troubled by the revelations.
“It's incomprehensible,” Thomas Hurter, Swiss People's Party MP from Schaffhausen told Blick newspaper.
“A conscript has a particular responsibility for his gun.”
Chantal Galladé, Socialst MP from Zurich and a member of the federal parliament's security policy commission told the newspaper it was necessary to stop the home distribution of army firearms immediately.
It is very troubling is every year there are tens of army weapons left in public places every year, she said.
The annual military police report also revealed there were 242 “incidents” involving weapons and ammunition in the first nine months of 2015.
Additionally, there were 13 military traffic accidents during the period leaving three people dead and 55 injured, the report said.