I purchased these thinking they were 45mm cannon primers. However, they are just a little to big in the rim diameter. They are marked with dates of 1940 and 1938 "G" for God or year. They are also marked "42-M". What did I buy? I am guessing they are bag gun primers, but I do not know of any Russian WWII bag charge artillery. All the rounds up to 152mm used brass cases for obturation.