Thread: See separation?

I have a SAUM 180gr running at 3050 fps with up to 12 firings per Norma brass.....no issues yet.

There appear to be heavy vertical scratching on all the necks, and my guess that is replicated inside too...could be huge stress at the point of separation if those necks are as tight as they look. Do not pull your expander up through the re-sized neck......remove it from the stem, punch out the primer, clean the inside with a brush, lube the inside of the neck with something like sizing lube, then install the expander and press down from the top. Even better get a K&M expander to do the job.

The other notable marks are at the top of the neck...quite shiny while the rest of the neck is overly black from gas leakage. Properly sized and annealed necks should have very little powder residue, and in fact if all the planets have aligned you should get witness marks on the neck from the powder representing the number of bolt lugs....! Have you checked the overall chamber length to the top of the neck and the headspace of your loaded round compared to a newly fire-formed case...best to have half to one thou clearance at the shoulders, and 10-20 thou at the top of the neck. That is not critical as long as all the brass is trimmed to the same length.. Also ensure there is no carbon ring formed at that critical junction of the neck and freebore.......?

Regarding annealing....it is difficult to over anneal except if the heat migrates to the base, then you are in trouble.It is not detrimental to cool copper and its alloys so get that heat down past the shoulder base....heat the neck and shoulders very quickly, and dunk it to prevent the heat migration. Lapua brass has very clear and consistent annealing evidence.....replicate that and you are on the right track.