I shoot a ak47 in 3 gun matches and have turned to cast boolits in an effort to reduce costs. the only problem I have is that at 50 or 60 rounds the lead buildup in my gas block hinders reliability. I use scrap lead water dropped with a brinell (spelling?) hardness of about 16. I use lee tumble lube bullets with an aluminum gas check. any ideas on how to clean it quickly or get rid of the leading?