I have no idea what book y’all are talking about, but does it specify that the rifle projects antimatter in any way? Maybe it uses antimatter in place of chemical propellant to fire a slug really fast? (and some handwavey technomaterial to contain the pressure)
Starbucks is a real coffee chain that exists in the real world. Moondeer and sunfawn follow the same naming scheme, but the players didn’t realize that was what the DM was building to until the big reveal. It’s…pun-adjacent.