I use .30-06 for most of my cast bullet loads, lube the inside of the necks with Imperial Sizing Die Wax and run them into your .35 Whelen die. I've tried Hornady dies with the zip spindle and am not a fan. I prefer Redding FL sizing dies and Hornady seating dies with the sliding sleeve. I checked concentricity using this die combination and found none that exceeded .003" TIR. I get excellent groups too with 200gr. & 225gr. bullets, powder of choice is IMR 3031 with 200gr. and IMR 4064 with 225gr. bullets. Good luck with your Whelen, I've been shooting mine for nearly 30yrs. it shoots everything well, cast, jacketed and pistol bullets. I've harvested whitetails with both 200 & 225gr.bullets performance was outstanding.
