I have a RCBS 7MM 168gr mould. It's throwing bullets that with GC and lube at about 180gr. The BHN I tested was right around 20. 1st question is how do I get my melt (which is scrounged WW) to throw lighter bullets? I can't find load data for a 180gr 7mm bullet. To go with that question, is 20 BHN good for a rifle bullet? I'm mostly going to shoot paper and steel with velocities about 1800fps.