I wish I could remember where I read it, probably a sign I'm reading too much about it. I think it said these guns harked all the way back to WWII. As an old reloader, I can testify that propellant doesn't last indefinitely...The D-30 is a venerable old Soviet cannon. Less range than the 152mm cannon, and packs a smaller punch, but the Soviets made a bunch of them. Not sure about the ammo.
When I was in the Army, we went to Guernsey, Wyo. (National Guard training installation) and fired some 81mm illum rounds. That charge cards (tells you how much powder to use at which elevation to hit a target at a various ranges) were dated 1945. The rounds all fired but the illumination was yellow, not white.