100-150, until the towel gets full, maybe 30 minutes, go in (cast on patio) and have some iced tea & computer, back out picking up those cast boolits, and cast some more, until the towel gets full, repeat...
I set mold on top of furnace to pre-heat, and generally get good boolits first try...
I cast about 50 of these this AM for my son to check out for his .308 - WW+2%Sn. Will cast a couple more different boolits and let him decide which he likes best...