Re: redding die bushings
The tech at redding told me to measure the neck of a loaded round of the same brass I will be reloading and subtract .001 to .002
Mine miked out at .367 so I ordered a .366 and a .365.
It is recommended to get a few because every lot of brass you load could be a little different. You also need to have more neck tension if you are loading for an autoloader so you may need an even smaller bushing. For accuracy usually less tension is better, for ruggedness more tension is better. I bought the nitride from midway for $22 bucks(the steel are $12 and probably would work every bit as good!!)
Good loading, Brian.