I was digging around in my bring home brass and discovered that I wound up with a handful of my cousins 9mm brass, (I load for nothing semi auto yet) and looked at it in passing and said "that ain't round". Sure enough, measure one way across the outside of the mouth and it's .3735 and the wide is .3865. Grabbed another, yupp pretty much the same. Should I be worried about his new pistol, or is this normal for a semi auto? Opinions welcome