Hellsbreath gun

This device consists of a powerful pump activated by a blast of powder that sprays a reservoir of alchemist’s fire in a line that is 20 feet long and 5 feet wide. Any creature in the line must make a DC 15 Dexterity saving throw. On a failed save, the creature takes an additional 1d4 fire damage at the start of each of your turns; the creature can end this damage by using its action to make a DC 10 Dexterity check to extinguish the flames. On a successful save, the creature takes only 1 fire damage on your next turn and does not take additional damage after that. Those who are not proficient with firearms tend to favor this weapon, but it is dangerous to use. Each time someone fires the weapon, roll a d20. On a roll of 1, the reservoir of alchemist’s fire within the weapon ignites and explodes, destroying the gun and dousing the wielder with alchemist’s fire, inflicting 7 (2d6) fire damage immediately and 3 (1d6) fire damage at the start of each of the wielder’s turns; if the wielder succeeds at a DC 20 Dexterity save, they take only half damage from the explosion. The wielder can extinguish the flames and end this ongoing damage by using their action to make a DC 10 Dexterity check. A hellsbreath gun requires two full rounds to reload. One must use two hands to load and fire it.