Quote:
Originally Posted by marxman
Whe i started reloading i got neck size dies and my full length dies i adjusted to the right length but the brass doesnt all behave the same and i got tired of rounds that didnt want to chamber. In 8 chamberings and over a dozen different rifles i reload for since i started sizing down to the shell holder i get pretty good case life and never get head seperations after some neck fails i throw a batch out. The op says he has to size it down that far for it to chamber so if the body taper is landing with the shoulder still too far forward maybe the chamber is out of spec.
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Like people, all firearms and sizing dies are individuals (and the reason I always say YMMV).
Similarly, there is wide variation between designs and results of ‘neck size dies’.
Most FL dies have similar function and design, but output size can vary much more widely than we would prefer, (or expect given that they are supposedly built to SAAMI spec). All dies are subject to manufacturing and QC variability.
I have >6 different 308W FL sizing dies, (3 Redding, 2 RCBS, & Lee). The Redding FL dies produce very similar (carefully measured) output size, but the others vary widely and the Lee FL is actually smaller than the Redding or RCBS SB FL dies, (as per YMMV).
As you suggest, “the brass doesn’t all behave the same”, (again, YMMV).
In addition to sizing die and brass variability; seating, and particularly crimping procedures can alter the shape of case shoulders and/or necks and cause difficulty chambering.
Chambers do vary (sometimes widely), for many different reasons.
Few reloaders have the tooling required to rechamber, but thankfully this is seldom required.
Our challenge as hand-loaders is to produce cartridges custom fitted for best performance in an individual chamber.
Most fitting (like voting) is a matter of choosing the best compromise considering all the factors and available options.
Good Luck, YMMV.