I do not trim every time, or even often. I do check a number of random pieces each time to see if I’m approaching too long though. If I am, then I trim every piece. I typically do not see a whole lot of variation in growth from case to case. I also don’t see much variation in SD/ES between trimmings, but keep in mind that I am not shooting benchrest comps. That might make a difference in your approach.Most times I don’t trim. I don’t know that a few thou makes much difference at all.