Talking of late to several shooters about the importance of case trim length and getting several " this is important" answers from all, I was chewing the fat with a gunsmith buddy this morning , musing about different chamber lengths of my various match rifles - three to be exact.
All rifles have been barreled by top shelf gunsmiths, a Remington 600, a Musgrave target, and an RPA Quadlite.
All are very accurate, although all have higher round counts
All have .223 Wylde style chambers ( one being chambered by Bill Wylde himself) , but all vary in the actual chamber case length!
The interesting thing is, that even with a case that is overly long (1.765), none of the chambers is too short to accept it .
The bottom line at the end of the discussion was as long as the cases are consistent length and fit , a rifle can be made to shoot accurately as long as everything else is taken into consideration as far as balance is concerned, for instance , a quality barrel, action, sighting system, and an operator that knows how to shoot to begin with!
I really think we complicate some things when hand loading and shooting for accuracy.
Several accomplished SBR shooters I know only set their dies so the bolt will close with a very slight pressure , that's it- no gauges, no measuring !
That is how I have done it for many years , but many disagree with that system .
Cat