Help with odd looking brass after full length resize

[Brians356]

All mine in every caliber look like that

Mine, too. I was getting watery eyes peering at those cases, trying to spot what was unusual. They certainly don't have the telltale "bright shiny" ring indicating an incipient separation. (Should be verified using the paper clip feeler described elsewhere.)

"Bob with the 66",

When you "full-length size" do you adjust the die in the press to slightly "cam over" against the shell holder at the top of the stroke? It's possible you are not really getting 100% if the sizing out of the die. (Nor should you necessarily want to, pending case measurements to compare length at the shoulder for fired brass vs resized brass. I prefer to only set shoulders back ~0.002" when sizing, and use a set of Redding Comp. shell holders to control that.)