I help someone move an old HD about the size of a dishwasher. The thing was VERY heavy. We struggled it out of the place he got it, into my van, out of the van, and into his basement. We found, mounted on the bottom, a solid piece of lead about 4”x12”x12”. Lead weighed 100 pounds.
Since the thing was top heavy, it needed a counter weight to keep from tipping over. Removing four nuts could have saved us a lot of grief. I got the lead. I loaned the lead to someone years ago and I haven’t seen it since. He probably made 100 pounds of bullets.
4”x12”x12”
approx equals 10cm x 30cm x 30cm.
one liter is 10cm cubed ... so you are talking about 9 liters volume
One liter of water is one kilogram
Density of lead is around 11.5 ...
so your lead block was a bit more than 100kg ~= 220pounds