I guess it depends on how they were stored. A few years ago a friend of our family asked me if I would be interested in some old ammo that her father had in his 50's ( Civil Defense Fall Out Shelter ) that he had built in his basement. She was cleaning out things to move and found this ammo. Of coarse I didn't pass up something for free, especially gun stuff. These were all unopened and like new.
1 brick (500) Remington Hi-Speed Kleanbore 22 Short HP's ( black lead tips ) & ( red & green box )
1 brick (500) Winchester SuperX 22 LR Shot Cartridges ( white & blue box )
8 boxes Winchester SuperX 218 Bee HP ( yellow & blue box )
6 boxes JC Higgens 12ga # 4 Shot paper shells ( blue & red boxes )
Of coarse I asked where the guns were. She said she didn't know. DAMN!!! I can only imagine what he had for guns. Oh well, I couldn't be that lucky.
Anyway's I have shot some of the 22's and they shot just fine. The 22 Short HP's are a blast to use on small game. They sound like Sub-Sonic's, very quiet.