Mehavey that is interesting. I checked my "RCBS Cast Bullet Manual" and they do not list the BHN for 30:1 but they do list 20:1 Lead/Tin as having a BHN of 10. There looks to be some disagreement on the subject. My "Lyman Cast Bullet Handbook" also does not list 30:1. It lists 10:1 as having a BHN of 11.5. As far as calibration for your Lee Hardness Tester I don't believe there is one. If the ball that is pressed into the test alloy is of correct size then the only variable would be the spring pressure on the ball and the amount of time the pressure is applied. I believe over time spring pressure will deteriorate if kept under stress. How long that would take I have no idea. If you read the tests conducted by the Los Angles Silhouette Club on the different hardness testers you will find the Lee Tester came out very favorable in consistency. I do have one of the Lee Hardness Testers and am pleased with the performance.
Shooters. We are a community. United we stand divided we fall.