I recently bought another slot of these on sale for $83 shipped and realized I didn't know what the hell the writing meant on these cans. Being the mentally bored person I am, I did some research and came upon the photo below.
This is the code only for Russian/Yugo/Czech ammo, but is still useful info.
This is a good source of info as well: http://7.62x54r.net/MosinID/MosinAmmoID01.htm (it gives a bunch of ammo specific information)
As for the cans:
These things are sealed against air/gas/water. In this can in particular, each can comes with 440 bullet, packed in 20 count pouches of paper. To open, you need the "tool" or a flat head screw driver and metal sheers (sharp sharp sharp!)
They are corrosive (not terribly though, and if you clean your gun like you're supposed to you'll never see an issue)
"max effective range" is claimed to be 500 yards but I've taken them well passed that (over 1000 yards)
If you see these full cans of ammo, I say buy them while you can. Ammo has gone up horribly in cost the past few years. When I first bought my M44, I bought a can for $49 at a mom and pop gun store.
Michibacy