I was taking my father-n-laws change to the bank and I had a nickel that kept getting spat out of the automatic coin counter. I didn't think much about at first until it did it a third time I thought it must be Canadian. After looking at it I noticed that it had a very deep impression on both sides as the rim of the coin was raised and sharp. After looking at the coin further I noticed that on the side of the coin it appeared to have been 2 slugs, as if it didn't spit the coin out or it got stuck on the die and smashed into another slug. The nickel is from 1964 but does not a have mint mark on it, unless it is in a different place than the newer nickels. I will post pics of it when my wife gets home with her dlr camera because mine doesn't seem to want to take a micro pic. Any info on this coin would be wonderful.
We look forward to seeing photos of your coin. By the way, the mintmark on your coin (if it has one) would be on the reverse to the right of Monticello.