Look in the yellow pages under "Glass Stained and Leaded". Us people that make stained glass windows for a living usually have a ton or so to get rid of after a few years of work. It is easily recycled but unless you have a fork truck it is not so easy to move a barrel full it. Makes great wheel weights for the garden tractor. Make a plaster casting of the wheel, melt and pour in a DRY mould. Make sure you allow for the bolt holes because lead is not easily drilled.
And yes be careful when handling and melting. Dust from old oxidized lead is VERY easy to inhale. It is easy to melt in a cast iron ladle. The melting point is 621.5 ーF. Please do not do this indoors or with children present. Lead is a dangerous metal but common sense when working with and handling this metal is not a problem. Wash your hands well when finished and clothing should be washed separately from other laundry. Please handle with care and keep children away from lead.
Jim