The nice thing about lead shot is that it is very dense and very cheap (although not as cheap as dirt ). I don't know the numbers, but a bag of shot probably weighs four times as much as an equivalent bag of sand.

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8