Some DA was stored all those yeasr in the ammo bumkerof a navy ship. Always nice and cool, but never frozen. Other ammow as stoed above ground and baked all summer and froze all winter.
So how it was stored turns out to be more important than the year or lot number.
IVI 7.62 would usually go bang. Most bullets have cores. Most primers are in the right way. Bullets tend to be a bit undersize compared to most barrels - around .307".
I have found some lots of IVI 5.56 that would shoot 1" groups in my target rifles.
We were testing some 5.56 ammo for a police contract by shooting it through a AR15 with a 9" barrel. We were testing for muzzle flash, so had the flash supressor off the rifle. It had a 24X scope on it, shooting off a bench at 200 yards. All the 10 shot groups were under 2". That anecdote has nothing to do with your question. It just came to mind because it has been my experience that the only way to know how a given handful of ammo will shoot is to shoot it.