I'm starting to acquire parts and equipment to build a 17 Fireball. I have 300 pieces of Remington brass in 221 Fireball to be necked down to 17. I'm going to buy Redding dies-neck sizer with the bushings. Questions: What size bushing is appropriate for the R-P brass and Hornady bullets? Is it necessary or advisable to use a larger bushing as a step in the necking down process? Thanks, Steve