@TroyG, here is my chicken scratch notes comparing virgin pieces of each piece of brass.Does the new 284 Win Lapua brass mimic the 284 Win dimensions and the Lapua 6.5/.284 Norma will be bigger?
That’s what I run.Would a reamer cutting .501 at the .200 datum be too loose?
Your reamer neck size is strictly relative to a) are you going to shoot turned or no-turn brass and b)if you're turning, how much are you going to take off. Just about any neck size in a given caliber can be 'made to work' but .317 is just a relative number to how you do or don't prep your brass.getting ready to order a reamer, .317 the best neck size for lapua brass?
John Hiller
No turn means you need to get a .320 or .321 neck.no turn, simplify the older i get
a new rule of mine