BobbyD, I’m not sure I would want to use cast copper. The idea is to swage copper as opposed to casting lead. To cast cooper you would have to have a furnace capable of around 2000 degrees. Lead only requires over 620 degrees. Not sure I would want to stand over or even fool with a 2000 degree oven trying to melt copper. Although there are instructions online for backyard copper smelters. And eventually someone may want to try it.
For copper swagging into bullets see http://www.corbins.com/intro.htm“> People have been doing this for years.
Now, my unofficial opinion on lead availability is that it will be a couple of years before it starts getting really lean. Of course I could be wrong. We are still getting lead from our local recycler for about .30 cents a pound. You can still find wheel weights, which are nice to have, but they are starting to become scarce in some areas of the country ever since the manufacturers switched over to zinc. As was mentioned, if there is dirt or other impurities it should float to the surface. And some states have outlawed the use of lead wheel weights and well as lead ammo, like California for example.
Anyway, look for lead from recycling places, salvage from shooting ranges (usually outdoor), wheel weights, old plumbing, online purchasing, old flashing from old buildings, old lead shielding from medical supply businesses, etc. Did you know the keels on some of the older boats use to be lead? And when I was a kid we used lead weights on our crab pots to hold them down. These are just some ideas. One thing has come up before, so some of you already know how I feel about it. But for some of you new to this topic, I strongly suggest you stay away from batteries. Whatever you be creative, and happy hunting.