Just to clear up the date thing - in 1982 they started making pennies mostly out of zinc rather than copper because copper was becoming more expensive. There is still some copper in newer pennies, but they are mostly zinc. The new pennies will press just fine, but sometimes when they are pressed you will notice a kind of streaking on the penny caused by the different metals.
Its not that the new pennies don't work, they can just turn out a little bit streaked. For most people that is not a major deal at all, but if you want perfect pennies, then try to get some pre-1982 pennies and shine them up.
Its not that the new pennies don't work, they can just turn out a little bit streaked. For most people that is not a major deal at all, but if you want perfect pennies, then try to get some pre-1982 pennies and shine them up.