i recently picked up 100 rounds of Norma 7mm rem mag brass. I wanted to do as much case prep to ensure uniform cases. The question I have is that I measured headspace using a hornady headspace gauge and the rounds varied from 2.106-2.109 which is a .003 difference. If I were to trim the cases to a trim length of 2.490 wouldn't that mean that some of my necks would be .003" shorter than others? Because the difference in length is in the shoulder or case body and not the neck? I sorted the batch into three groups that had very consistent headspaces and went ahead and trimmed them to 2.490. Should I recheck them after fireforming and trim again or should I have waited to trim until after fireforming and the headspace measurements should all be the same...or am I overthinking this? Thanks for the replies!