It is because every time a piece of brass is fired and re-sized, it could “stretch-out” or lengthen. Employing a case trimmer can get it back to teh right size. We’ve compiled a list of the Best Case Trimmers for you. Neither of these are generally worries for handgun cartridges. https://damienncmty.ourcodeblog.com/30788458/the-ultimate-guide-to-hunting-supplies-uk