Have fired many boxes if WWB in 9mm,38 special,40 S&W and 45 acp. Never had a problem with it in any of the calibers listed. Fired exactly one box of Ren-Umc in 9mm luger and that little escapade cost me a new firing pin for my Beretta 92FS. And that is the reason for my changing to WWB for most of my pistol shooting. Frank