I was recently loading some 45 acp using Lyman carbide dies. I noticed on some of the brass I was getting a very fine line around the bottom of the brass. It went about a third to half way around the case. It was at the bottom of the case just above where the rebate starts above the rim. You can feel it with a thumb nail on the outside but not with a paper clip on the inside not all of the brass had this line. It was range brass I bought here on the high Road. Any ideas what caused this and is the brass safe to shoot. Thanks for the he;lp on this.