RE: shooting old shells?
10 years old?
No problem. They'll likely shoot just fine.
Unless ammo is kept in a very humid condition or very warm (hot) it usually ages ok.
I keep all my ammo in miltary ammo cans in a corner of the basement that is kept cool and dry......I have some 8 X 56R ammo that is marked with the year 1936. It goes "boom" everytime.