New to reloading... I am reloading once fired 300 WSM cases. I full resized a dozen or so a few weeks ago and found that when chambered the bolt closed hard. I posted my problem here and had several responses suggesting that my die was not set up correctly or possibly needing to have the head space of my rifle measured. As it turned, out after visiting with a local gunsmith, I did not have my die adjusted correctly. It needed to be cranked down into the press more. As suggested by the gunsmith, he instructed me to set up the die per manufactures instructions, resize a case then chamber the round, if the bolt would still not close, readjust the die (small increments at a time) and resize... doing this until the case would chamber without resistance while closing the bolt. So I have the die set now to resize a case that will physically work. Is this good enough or do I need to be concerned with the "head" to "shoulder" dimension? I would assume that if the case was resized just to the point to where the bolt closes, I would not have under sized it to the point to where there is too much head space? I have calipers, so I can measure the overall case length, but I do not have any accurate way to measure the distance from the head to the shoulder. I see Hornaday makes a device that attaches to a caliper that will measure that dimension. Am I splitting hairs here or?