Thanks guys, its rare that I throw anything away 
If you haven't got an solid copper bar (which isn't all that common to have laying around) copper plumbers pipe filled with molten lead is easy to do to make a nice heavy copper/lead hammer.
You can leave it as is or solder/braze copper end caps on it.
Of course, if you're like me, you judt pick one up at a yard sale. Amazing what people don"t want.