First time reloader, and I have some questions about how to choose the correct bushing sizes for use in a Redding Type S FL die for my .25-06 hunting rifle. First, I have new Winchester brass and will be using Speer 120g Grand Slam bullets, and as part of the initial brass prep, I will be turning the necks for consistency, and will be aiming for a .015 thickness, as recommended in Doug Arnold's excellent book on achieving accuracy. Based on this, in order to know what size bushing to order, do I just add the total neck thickness (.030) to the caliber diameter (.257) for a total of .287, and then subtract the amount of neck tension that I need, such as .001, .002, .003, etc., from the .287 total? If doing it this way is not correct, or maybe not accurate enough, then how should I do it? Also, is it recommended to buy more than one size of bushing? Is there any advantage to buying the Titanium Nitride bushings versus the steel bushings? Finally, and you probably knew this was coming, which bushing size or sizes would you recommend that I buy?