The D-Day Bullet
This item was the first bullet from a German Mauser rifle fired at Utah Beach that killed a member of the American military. There is a lot of occult discussion as to just who was the first real casualty of D-Day; as a result, there are several items that can be plausibly claimed to represent the first fatal shot made against the Allies that day. This particular Bullet, however, is so powerful that it almost glows in the dark for non-magic users, so there’s that.