I had the same problem, the place I bought lead only sold it in ingots about 2 foot long and 5 inches square, they weighed about 50 pounds. I used a brickies bolster and a 2 pound club hammer. Give the blade on the bolster a good rub with some bee's wax, it helps it pass through the lead without sticking. Use a good solid anvil or sit on a good solid cement floor like I did. You really need something silid to work against otherwise the energy from the blow gets wasted moving the lead.
Ron.