|
Yes, it is necessary to check your resized cases for the correct head to shoulder distance, often called case headspace.
Standard full length sizing dies usually set the fired bottleneck case shoulder back way too far when the die's set in the press such that the shell holder stops against it (as most die set instructions state) when the case is full into the die. Depending on the die and shellholder used, a sized bottleneck case may well be smaller than SAAMI specs; you won't know unless you can accurately measure it to a 1/1000th inch accuracy. Your rifle's chamber may be at the long extreme of chamber headspace. Sizing fired cases back to SAAMI minimum (or more with some dies) ends up with excessive head clearance (space between case head and breech face when the round's fired) and case life will be very short and accuracy will suffer.
Using a case gauge, such as the RCBS Precision Mic or Hornady Lock-N-Load (case) Headspace Gauge, one can measure their sized cases then compare them to a fired one to see the difference. Normally, best accuracy and case life happens when the fired case shoulder gets set back 1 to 2 thousandths of an inch.
The Wilson case gauge cannot accurately measure that small of a tolerance as it depends on the eyes of the human to resolve that tiny measurement. Besides, all the Wilson gauge does is compare a case to SAAMI specs (as Wilson makes their gauges to) and does nothing to ensure the case is full length sized best for your rifle and best accuracy and long case life.
|