Picked up some 300 win mag brass at a gun show. Should've looked closer at the heads, looks like pressure signs and now I'm thinking they weren't once fired like I was told. Hopefully the picture will show, on the left side you can see the brass being extruded into the ejector hole and on the right there's a dent at the edge of the rim. About half the bag looks like this.. Does anyone know what that dent could be and if I'm ok loading these cases?