Re: WTB-338 Lapua Redding Match Type S 3 Die set**Found**
In the competition neck sizer dies (no expander) I pay very close attention to this. I have gone to the type S as I don't neck-turn and the expander (in theory) should give me more consistent neck tension.
To make a long story short, it made me lazy. I had no idea how much springback was being built in. Your post got me off the couch to go check.
On my 338 LM set, the expander mics at exactly .336. This should give 2 thou of springback when loading. With the .366 bushing I am definitely engaging the expander (the .367 just barely engages it). In my simple mind, as long as the expander is opening up the neck on the way up, I should be good to go (ie if I sized a few thou tighter, the ball is still going to open it up to the same diameter on the upstroke). I could be wrong on this? In any case, I have had no issues with bullet movement in the magazine.
If you were going to go with no expander, .366 should give you an additional half thou or so of additional tension (assuming your brass = my brass).
Hope that helps.