Powder coating done well creates a slick surface on the bullet that also will survive the trip up the barrel very well. There are no drawbacks to the process. On sizing, cast bullets should be 1 or 2 thousands over bore diameter and you can run the bullet after coating through a Lee Sizer die if you wish. Since this is a 458Win Mag thread, you will find most off the shelf molds are .458 or .459 sized so the Powder coating helps get the bullet up to the .460 / .461 that you really want anyway. Of course you order custom molds in the proper diameter as well. Fear not. Coat away.
Thanks for the info. The rifle bullets are Cast Performance gas check .458. Though I have not confirmed the actual size. This seems to be the way to go.
The smoke reduction as jwp475 mentioned, would be particularly welcomed with the bigger bore revolvers.
