here is picture of deformed brass, also it had unadjusted firing pin which did create similar craters


and craters and ejector marks



after I adjusted firing pin, the cycling issue didn't go away. Here you can see ejector marks, but almost no craters



to check for headspace get candle and smear some carbon on the shoulders of fired brass and cycle it in your action then remove it, if shoulders of the brass had full contact with the chamber it will indicate tight headspace, if no contact then it will point to excessive headspace



o yeah, forgot to mention the chamber I had was also 5 thousands off center with the bore, so it could also contribute to hard to cycle cases.