Originally Posted by William
I noticed the primers were backing out of the cases, apparently the cases were not stretching to the
bolt face and reseating the primers.
Nothing (generally) wrong w/ Winchester brass (at least in my experience. Others have different tales.)
That said, I'd first get a headspace check if the primers have that much room to back out.
Once checked (and if in spec), I'd suspect un-annealed shoulders/necks on the cases
-- AND/OR --
the rim on the brass is not thick enough to handle the kind of lockup you're dealing w/ if you're shooting a lever action.