I hope I don't irritate any of my friends by pointing this out, but:
In post #2, Kuger asks the object's finder (Ninjafossils) if the object is solid. In post #3 the finder replies that it is "solid, heavy, and dense." But people continue to guess various kinds of hollow objects (like a bullet-casing, or a shotgun shell). What have y'all been smoking? ;-)
Edit to answer Ninjafossil's question -- he wrote:
> But is it a round, and is it dangerous?
No, it is just a piece of 100%-solid (not hollow) brass or copper, and being solid it cannot have anything inside it, and thus is not dangerous. The lip on one end of it means it is a type of "locking pin" -- similar to (but much smaller than) a trailer-hitch's locking-pin.