Basic lepton agitator with bolted on Faddeev–Popov ghost field smasher.
As you can see, this basic ray gun has been modified and augmented with an experimental *quasiparticle disrupter. It's designers evidently then had second thoughts, as evidenced by the alarming number of warning stickers affixed to the highly experimental weapon.
In theory this weapon may have an infinite range, the beam endlessly travelling through the universe, unraveling the fabric of reality as it goes. On the other hand, as one sticker says, it might all be FINE.
Running off a basic hand portable fusion station, housed in the rear of the gun, the user need never fear running out of power. However with so much else to worry about, this is little comfort.
Not to be placed within reach of children, a basic knowledge of exotic particles is desirable, though not essential. Best to be sure the target is nice and far away, with no significant celestial bodies directly behind them, including of course, the planet we are standing on.