Not the regular 9mm vs 45 thresd...
Have you noticed a need for harder lead in the 9mm?
I ask because I cast some bullets using essentially the same lead for both calibers. I am happy with the results in the 45. But the 9 mm is giving significantly more leading of the barrel.
The 9mm were made with the Lee 124 grain FP tumble lube mold, and sized with the Lee .356 sizer. Bullets were tumble lubed and loaded with W231 at 3.6, 3.8, 4.0. Near the end of testing about 80 - 90 rounds, I noticed the bullets were tumbling with the 4.0 charge.
As near as I can judge with the Lee hardness tester the bullets are about a BHN of 14.