OK guys. I read the 1 posting & did an experiment: I took the 26 Win .270 (RP) cartridges that did not open their ID after firing and made 4 batches: Annealed & sized, Annealed only, Sized only, and NOTHING: just re-loaded as fired. Results were surprising: 100 yd spread: no trend. Cart base: no trend. Case-mouth opening: no real trend. BUT:
From these 4 batches, AND 4 new WW factory 130gr rds:
FACTORY: all 4 rds yielded narrow necks!
Annealed & sized: 6 of 11 yielded narrow necks
Annealed only: 1 of 5 gave narrows..
NO sizing OR annealing: all 5 gave normal, open mouths (verified all by testing with std, measured .277 OD bullet.
HUH?
?? No Comprende!!!! Any ideas, one & all??? :?:
