Pic number two.

Probably should use a bore scope to examine your chamber to see if there's anything there that caused this?
That said, I wont ever buy Bertram brass again. I bought 40 expensive .25-21 Stevens Bertram brass and lost 20 of them the first firing. I pulled the others apart and dumped the powder and never used them. Contacted BACO about what happened and got no reply back at all. The load I used had been used for years with old original brass and never lost a single case.

My Peabody .43 Spanish leaves the odd cosmetic ring on the brass also.  These (and the Rolling Blocks) were mass-production military arms, made to conform to Government contracts that would not specify the condition of the fired shells for reloading since nothing of the sort was contemplated.  In the interests of speedy production, the factory was not above crowding the chambering reamers a little, with the effect you note.

Congratulations on the complete survival of your brass after firing.  I remember my first box of Bertram .43 Spanish brass lost 8 of the 20 with body splits on the first firing.  You did a good job of annealing.

When one of your shells does take early retirement, you can drill and tap the primer hole, attach a piece of threaded rod with lock nuts, smear the case with Clover 320, and spin it slowly with a variable-speed drill in the chamber while pushing it in and pulling it out slightly for a minute or so.  Clean thoroughly after the operation.  That should clean up the ring so it isn’t so visible on the brass any more.

I myself ignore the chamber marks on my brass and just go on reloading.  I haven’t had to full-length resize them at all.  The chamber rings I have are not like a pressure ring from a wad over smokeless, or  a stretch mark at the base that denotes excess headspace; it doesn’t seem to get deeper or worse and doesn’t result in cases sticking in the chamber even after many reloads.

BlackPowderBurner wrote on Aug 9^th, 2025 at 7:14pm:


Do as mentioned and make up a cartridge by drilling and tapping the primer pocket then thread in a 1/4" rod and a jam nut to lock it. Spin it in the chamber with some lapping compound and you'll probably get rid of the line or ridge. Concentrate the lapping compound on the same area on your lapping case and clean every so often so you can check it with your bore scope. You can get this to where it's not an issue.

Whatever you do, don’t full length size your brass with the Lee dies.  They will over work the brass!  I shot my Bertram brass 5 times and never had an issue with the cases.  I only neck sized them.
Cheers,
Steve