I have just began sizing with the micro adjustable Redding die but after sizing the necks in a ladder type style, sizing only 1/8 from the top down, increasing the depth of the sizing by .025 increments until I was sizing nearly 80% of the neck I really didn't notice any difference. I must say that I do not have a chrono so if the difference is in velocity because of the pressure increase, I would not know. At what size do you that use the adjustable neck sizer, size to? I have sized down by both .001 and .002 from the loaded case.