In the Army I've always heard the myth that since our intermediate mortar is 81mm the Soviets designed theirs to be 82mm so they could fire captured rounds if necessary. I was wondering if there was any truth to this or the idea that to Soviets would in general "one-up" the US so they could utilize captured ammunition?
Do you have any other examples related to American artillery? The soviets used mostly 122mm and 152mm field guns while the US used 105mm and 155mm guns. I have heard the same statement regarding the imperial Russian artillery calibers, perhaps it would be more likely that they based their guns off German standards or it is just an urban legend.