If quick's answer don't cover it, you may be looking at the rim running out. This means your chamber is.005" oversize and the loaded cartridge is laying in the bottom of the chamber loaded mode. This will cause a bulge on the upper side of the fired case. Many firearms have this quirk and nothing to worry about. Still minute of whitetail. Bench rest shooters may scribe their chamber face and cartridge rim to load the NECKSIZED case to the same point constantly. Called indexing the round, but a real waste of time in a single shot Handi.