I recently started getting ready to start loading for the AR I recently built. I have a batch of brass that I've resized that I'm having a problem trimming. The case length rod (Lee) won't fit into the brass-the case length rod goes in a bit but not near enough to trim, the necks are too narrow. This is only a problem for the brass that I've resized, ones still waiting to be resized the case length gage fits in normally. The only other rifle cartridge I load for is .30/06 and I haven't had this problem there. Am I missing something or did I do something wrong? The resized cases range from 1.763 - 1.766 so they're all a bit too long. I thought that maybe they were close enough then thought better about that.