Hello, first time ever on this type of site, so be easy on me. I am not new to reloading handgun ammo., but am new to rifle reloading, so here goes. I have a .308 Win. Savage model 10, 24 inch barrel, 1 in 10 twist. As of this post I have only fired factory loaded ammunition and I am using the once fired brass to set up my press, Dillon RL550 B. I have also purchased 500 rounds of once fired LC LR brass, obviously fired in a different rifle. I measured the brass fired in my rifle using Hornady case comparator tool on a dial caliper. They measure 3.727, relative measure given anvil and case comparator attached to caliper. From my reading I'm looking to size brass to 3.726 or there abouts? Please correct me if I'm wrong. I took great pains to adjust just so the length was right on the money. Tested brass in rifle chamber, works perfectly, no binding. My problem lies with the LC LR brass. Most of those cases measure approx. 3.735, remember the attachments on caliper, measurements are relative to difference from start to finish. If I run them through the die as adjusted for the brass once fired in my rifle they only measure 3.729. Without changing the die adjustment if I run them through a second time they measure approximately 3.726 +. Being that running them through twice got me where I wanted to be I tried running the brass through the die twice in rapid secession, and the measurements were closer to the measurements after only putting them through once. I then took three pieces of brass and measured them after they went through the die each time, the longer time lag seemed to make a difference in the final measurement. I want to do things right, but I wouldn't mind skipping a step if it's not detrimental to the process. I "ASSUME" the problem lies with the starting size difference between the one fired brass fire formed in my rifle vs. the longer case size of my purchased once fired brass. That being said would I be better off resetting the die so the desired size is reached with one cycle of the press for the LC LR brass? Then resetting the die after the brass has been fired formed to my rifle? Or should I leave it adjusted where it is and run in through twice? I did note that unlubricated brass does not change dimensions the same as lubricated brass. This happened accidentally after dropping a lubricated brass, which had been through the sizing die once, on the floor and wiping it clean, then forgetting to reapply lube to that one case. No matter how many times I put it through the die dimensions didn't seem to change much. I then lubed the case and the correct length was obtained. Please help me with some words of wisdom, or encouragement. Thank you for your posts on this site, I read many before starting, but quickly ran into an unforeseen problem.