In the original post Keef says that the bulge did not extend to the outside of the barrel. Now excuse me for being thick or stupid, which I often am , but does this not mean that the 'bulge' internally was actually a manufacturing fault and if the rifle shoots ok can be disregarded from a safety point of view?
A bulge just forward of the chamber in the thickest portion of the barrel will often not appear as a defect on the exterior of the barrel, either visual or by "feel".
However a bulge is easily identifiable inside the barrel as a black ring extending into the grooves. On this barrel it is definitely a bulge, not a manufacturing defect!.