For you guys that think any bulge is unsafe, think about all the cold formed parts that you come in contact with in regular course of your days in which your safety relies. Many auto parts that critical to the structure are cold formed. Thousands of aircraft parts in which you place your trust are cold formed.
Jon,
While a bulge in a barrel may resemble an aneurysm in a blood vessel, the materials of each are entirely different in their properties both before and after the bulge. The typical barrel material is a fairly mallable steel.
As for a bulge, especially a "slight" bulge ever openning up, I'm with Rocketman. If you were to test the steel in the area of the bulge, assuming it was not cracked, it would be harder and stronger than the other area. If it were, indeed, "slight", I'd have no reservations of having it reduced or even leaving it as Miller suggests. Some of you may recall the Rem 32 with the bulge that several knowledgeable members were after recently.
