You touch a firearm and imbue it with magic. Make a ranged spell attack, applying any bonuses from the firearm, such as a +1 weapon. On a hit, the target takes the weapon's normal damage (which is magical for the purpose of overcoming resistances) plus an additional 1d4 of the weapon's damage type. If the target is wearing heavy armor or has any temporary hit points, the damage increases by 1d6.   When you reach 5th level, the shot can bounce to a new target if it hits, using the same attack roll, and the bonus damage to heavy armor and temporary hit points increases to 2d6. These effects increase at 11th level (3d6, three targets), and 17th level (4d6, four targets). A creature can only be target once per cast.