I bought around 500 rds of used brass from gun shop a while back. When I polished and resized I noticed that about 50% of the brass had 12 to 14 fluted marks from head extending all the way up to shoulder area. These were visible and you could barely feel them before and after resizeing. I dont now if they came from manufacturing or from gun chamber on shooting. Seems they were all the same head stamp but I will have to go look since they were load 2 years ago and I havent shot any yet. Has any one seen these marks and have any idea where they came from. I dont know if they will disapear with firing yet. I dont think I need to worry about there safety???

They are from the manufacturing process; no, they will not go away; no, they are usually not a problem; when the brass does fail (eventually), it will be at one of the creases, simply because that's where it is the thinnest. HTH, Dutch.

The H&K semi-auto rifles had fluted chambers and marked up their brass that way. I've never heard of anyone having trouble reloading the cases.