I shot 6 rounds today of .45 in my Ruger commander and checked the ejected rounds. I noticed that at the mouth of the casing, there is an indentation as if the round was stepped on. It also had some scuffing or scratch marks on it. Can anyone give me a clue on what is causing this. I am using 4.5 gr. of Bullseye, large pistol Winchester primers, Berry plated bullets (.452) and a COAL of 1.250. The rounds are very lightly crimped. Any help will be appreciated.