noobie question on sizing

[Velosa]

Hi all. I'm new to casting, so this is probably a dumb question. I found it necessary to start casting, as I'm trying to get an old Winchester 1885 chambered in 32 ideal up and running. The bore slugs to .325. Just a tad oversized. I'm going to have a custom mold built to drop the boolits at .326. Is it OK to use a .326 sizing die (same size as the "as cast" boolit)??? Or do I need to make the mold drop at .327, and then size down to .326? Thanks in advance for your help. Don't know if it matters, but I plan on using wheel weights.

[runfiverun]

if i am gas checking i like some friction to help maintain pressure when seating the check.
if i am just sizing and not checking i still like them to be a titch big so i know i made them round and didn't just size part of the boolit.
the slightly bigger boolit also allows you to use the bigger diameter for a better static fit of the rifle.

[stubshaft]

+1 on what RFR said. I would get a mold that dropped .328 and size to .327 to make sure that the boolit is round. If later you decided to size to .326 that still wouldn't be a problem.

[Velosa]

Thanks for the replies!

[MtGun44]

I'd start with groove +.002 and try groove +.003, Mr Target will tell
you which is better. In rifles, you need to fit the boolit to the throat
area more than to the groove diam.

Bill