i buy scrap lead from the junk yard here and it always seems to have some anitmony in it.. just a tad seems to have similar effects as alot as in some other materials inb chemisitry applications.. cant verify this as i havent devoted alot of time to it.. but you will generall know if you have antimony by the biggist problem ive found with it.. it will tend to tear at the spru cutt off point.. thus leaveing a divot.. inside this tear you will see the granular surface your talking about.. hardness from the books ive read tends to be towards maximum (that is aproximat it keeps getting harder for awhile if i remember right) at about 2-3 weeks and i like to let them set at least 9 days.. ive seen charts on this and 9 days is very little difference from the harder bullets let set longer... you will notice as you size them from first day to 10 days that they are lot harder to size later on.. i have not found that casting types/ harness/ tiny deformities/ have caused much shooting problems.. i have shot quite a few one minute of angle or under groups from one hundred to two hundred yards this year with open (lawrwnce) sights with bullets with antimony in them. this is from a 500 grain round nose, with gas check, i leave the gas check off.. put two .060 vegi wads under it.. they love my 45-70..or vice versa.. . i have a spitzer mould that wont hold under 2 inches no matter what i do,.. with black powder the lighter bullets would not preform also.. so bullet design, weight,diameter, powder type and amount, number of vegitable card wads, number of groves lubed, and other factors are much more important than bullet hardness... i can see absolutly no difference in acccuracy between 20-1 and 30-1 in bullet hardness with good polished barrel.. .. i pick generally good bullets, not worring if they are pristene.. the base is the most important, with grouping weights together for testing.. good luck dave..