I'm looking for Winchester contact info and can't seem to located it on their website. The new 270WSM brass I purchased with the WW headstamp will not allow primers to seat flush without using excessive force and flattening the primer with the seating tool. It looks to me like the pockets were not sized properly. My Remington brass seats tight but does not flatten the primers. I'd like to have WW replace the brass but can't find any way to get in touch with them.
Brian
You should ream all of the primer pockets before seating primers with new brass, either Rem, or Win.
I had 300 Rem 30-30 cases that I could NOT seat a primer fully into the pocket. Same problem you have, only with Rem brass.
Buy the primer pocket reamer from Sinclair, Intl, and their adaptor so you can do the reaming with a cordless drill.
No need calling Win, as the next bag(s) they send you could be worse than the ones you have now.