Bugger,
My advice to you is to treat you new 35 Whelen just like it was a wildcat chamber, which it is sort of, and fireform your brass using the same sort of process you were advised on the 35 BW. New 35 Whelen Brass is notorious for being small and you want good tight fitting brass to get the most out of the rifle. If your starting with 30-06 brass which I do most of the time or starting over with the 35 BW brass, getting it to a good tight fit is where you want to be for your 60K PSI loadings. You know all this I am sure so Happy Loading and shooting!
The chamber is minimum/tight. If I full length re-size with the RCBS FL sizing die, the case is a snug fit in the chamber. I may, gasp, buy some factory loads to see how factory loads work. It is a difficult process, that is pulling the billfold out for the purpose of buying factory ammo! But if my kids get this rifle some day, I'd like to be assured that factory ammo works too.
The Brown Whelen dies are sold BTW
