11-15-2023, 12:04 AM
The starline brass has, IIRC, a slightly smaller interior volume. So using the "book max" hornady load is probably putting your brass over the Saami limit. That's why it is "faring poorly" so to speak.
When building a load any difference in components, from primer, to brass mfr, to even powder lot#, you don't simply put your load from an earlier work-up (let alone a max book load) and expect things to go well. Need to work up from a minimum or lower load first. And watch your MV, if you go over-max (as adjusted for barrel length) then you are above the pressure limits that the book (in this case Hornady) got for its MV/load... even if you are below that "book max."
When building a load any difference in components, from primer, to brass mfr, to even powder lot#, you don't simply put your load from an earlier work-up (let alone a max book load) and expect things to go well. Need to work up from a minimum or lower load first. And watch your MV, if you go over-max (as adjusted for barrel length) then you are above the pressure limits that the book (in this case Hornady) got for its MV/load... even if you are below that "book max."