We picked up about 150 pieces of brass from a shooting area. A few casings have striations (grooves?) that I've never seen before. They are like cut marks on hollow point bullets, and can also be seen on the inside of the casing. These are R-P 308 Win casings. The striations are most pronounced around the neck, as if they were made to allow easier neck forming. Some of the marks go 1/3 of the way to the base. I can't seem to be able to upload an image now. I will try again later. Anybody familiar with these marks? I said I'd be hesitant to do any reloading with these.