chris,
I don't do the PC coating, but bullet sizing should be the final step. I have sizing dies, .356, 357, 358, and depending on alloy hardness/mix, and thus bullet spring back, I select the appropriate die that gives me .357''. Also the length of time after casting will change bullet hardness and spring back.
.355'' at the bullet base is too small. You will need to expand the case neck, but be careful of running the expander in too deep as to affect the chambering of the brass.
Assemble a dummy round, and seat the bullet out to an oal of 1.160'' and see if it will pass the plunk test. Use a magic marker all over the bullet. If it will not plunk, keep repeating a few times and then look and see where the bullet contact is. This will show you what size bullet you need and how deep to seat it. Do this with the LRN bullets, as the have a larger bearing surface.
I made a mistake in my earlier post my mold is mp 125 rn.