I use both bottom pour and ladle, my bottom pour is an RCBS and does not leak like the Lees do, of course the RCBS one is nearly $500 so make sure you are doing it for the long haul before you shell out for this one. MY experience is that there is more weight variation in bullets from a bottom pour, esp the bigger heavier bullets, alot of folks that cast for BPCR find the same. For top accuracy, whether you cast them yourself or someone else does, weigh and sort them, I think that the weight discrepancy from the bottom pour will surprise you.