Thanks for all the advice. Think I have got to the bottom of it thanks to you lot.
If I chamber a case and very carefully draw the bolt back and catch the case with my finger before the ejector slams it against the receiver then they don't dent. the more aggressively I open the bolt the sharper the dent is.
the ejector is bottom left on the bolt face and the ding is top right, the machining inside the receiver is pretty sharp on the corner where the bolt lugs are cut into the receiver so that is the issue.
Dang, seems like it's going to be tricky to sort out, all my nice reload brass is getting dinged after each fire.
Wonder if I could reduce the ejector spring force? or just ignore the dings and keep reloading them...
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