- Thread Starter
- #21
Thank you for the comments, much appreciated. Is it safe to say that a case gage and comparator give you the same information, except the comparator gives you an actual measurement of headspace vs. a simple inside or outside specification reading? If so, it may make the most sense and increse consistency to get the comparator vs. the gage.The first step is figuring out an accurate measurement of what your particular chamber measures from base to the shoulder datum. If it’s already been fired once in that particular chamber then pick a short piece that’s under trim max, measure to the shoulder datum and write that number down, neck size it (or use your FL die and don’t touch the shoulder) and fire it again. If it doesn’t grow or only grows by 1-2 thou then your probably there as far as the brass completely expanding to that particular chamber.
It’s really important to have accurate number for shoulder bump and not over size your brass, I have seen case head separations in as little as 3 firings from guys camming over a FL die on a standard shell holder and pushing shoulders back 10-12 thou every time they sized.
lots of different thoughts on trimming, IMO it’s good to know your actual trim length in your chamber so your not trimming to short but you can also pick a middle of the road number between min and max and trim to that, or find your shortest piece of brass and trim everything else to match.
It depends on what type of trimmer you’re using, some base off the shoulder so you need either fired cases that are completely formed or good consistent shoulder bump to end up with consistent trim length. Others base off the case overall length so they are cutting pretty much the same no matter where the shoulder is at when they are trimmed.
Your plan sounds pretty good, you just need some hard numbers on your chamber before going to crazy.
Thoughts?