These are unsized as yet.
johngarnett wrote:they also display a slight internal ridge at ring point by using hooked paper clip.
I can't feel anything inside or out, with paper-clip or fingernail. [correction - I can *just* feel it on the outside with a fingernail, but I wouldn't describe it as 'catching'].
johngarnett wrote:it could be faulty brass at manufacture point? It is not case head separation.
I've now examined 2 cases with the ring under magnification, and I can see identical variation in the width and pattern of the ring around the case, so it's definitely a tooling mark of some sort, whether during manufacture or firing (rather than something more worrying, such as an inclusion or flaw in the brass material itself).
The measurements of the cases with the ring correspond closely, which seems to suggest that the marks have come from the chamber. In fact, the ringed cases have stretched a little more than most of the others (the shoulder by about 0.003" more and the case length by about 0.005"). The ring itself is nearly 0.050" wide, so I doubt it is related to that extra stretch. Perhaps that particular chamber was just a bit ropey all round.
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