I have seen two kinds of bulges. One the resizing die can deal with and the other the resizing die will cover up and give you a shell that is waiting for the opportunity to blow out your magazine from the frame. In developing some 45 +P loads to fire in my USP45 I have seen brass develop a bulge which is like a bubble at the web of the brass that meets the rest of unbulged brass with a distinct line. This shell either shouldn't be used or should be designated to be downloaded, fired, and left on the firing range ground. This may seem overboard, but I mark the headstamp of such bulged cases with permanent magic marker as a warning to other brass scroungers at the range. My experience has lead me to spend a little more time inspecting brass and keeping brass separate that is used for target loads vs brass used for high-power loads.