This thing is really fancy. It's got inlays of different kinds of wood and what you think is mother-of-pearl, the scope has adjustable magnification, and instead of a magazine it has some sort of power pack. In the Medium it will never need to be recharged or reloaded, which frees you from carrying around actual bullets! Which is good, because you have neither pockets nor any kind of convenient metaphysical game abstraction that could act as an inventory. Perhaps most importantly, you also don't have any bullets.
You do wonder why anyone would leave this super nice rifle behind, but oh well. Their loss is your gain!