I have a few things to try:
a. slug the bore again. Undersized bullets are a major source of leading and your results seem suspicous;
b. use a gas check, or use a plain base bullet. Gas checked bullets are prone to leading when their base is left exposed; and
c. once a. and b. have been addressed, lube and size them with Alox again - they might be underlubed.
Don't try to make the bullets even harder. Hard bullets are more likely to lead than soft, at the pressures you'll be getting from "The Load" (13 grs of Red Dot). WW is fine - no need to water drop. You don't really need gas checks either at those pressures.
