I am casting a 405gn .458 bullet from a single cavity steel RCBS mould. The bullets are dropping at 419 to 420gn and are around an 11 BHN. I am using 9 lbs wheel weights and 1 lb linotype for a mix. The bullets come out of the mould with a little frost on some, any that gas checks fit loose are discarded. I will powder coat once the gas checks and sizing is done. I am using a .459 NOE sizing die.
My questions are, will the frosting affect the ballistics. Should I use the loading data for a 405gn or the data for the 420gn lead bullets listed in the Lyman or the Lee manuals. Will adding 2 lbs more of linotype bring the bullet weight down. I am planning on loading a mild load to use in Sharps, Remington Creedmore and TC Contender, so hardness is not that important with the PCing and gas checks.
I have read some about frosting not being a big deal, but one person that has done extensive casting and competition shooting told me to remelt any that are frosted. Thank you for any answers.