One of the simplest ways to check the case and trim to the correct safe length is with a Lee Case Trimmer. After a case is loaded a few times, it will stretch beyond maximum length and must be trimmed.
Get the appropriate Case Length Gauge (Pilot) and Shell Holder for each caliber you need to trim. In combination with the Cutter and Lock Stud (order separately – you only need one for most calibers except .475 and above which needs the large size), trim cases by hand or electrically. Can be used with an elecrtric drill to trim, chamfer and polish cases faster. Eliminates danger of long cases. Squares the mouth for more accurate bullet seating and exit.