Deezil, it sounds like your swc are of pure lead. Way too soft. CAS shooters use BHN's of 10-12. With proper fit, there should be no leading. I don't slug bores, merely use the cylinder fit=no leading. You will find what works for you too. It is all good. For a bunch more information on cast bullets (boolits) go to www.castboolits.com
gramps