Firearm Adept (5e Feat)

Prerequisites: firearm proficiency
You have learned to handle firearms in more than ordinary ways

You learn two trick shots of your choice from among those available to the Gunslinger (CR) archetype in the fighter class. If a trick shot you use requires your target to make a saving throw to resist the trick shot's effect, the saving throw DC equals 8 + your proficiency bonus + your Dexterity modifier (if you are of a class that grants you a trick shot DC then use that instead).

You gain one grit point. These points are used to fuel your trick shots. A grit point is expended when you use it. You regain 1 expended grit point each time you roll a 20 on the d20 roll for an attack with a firearm, or deal a killing blow with a firearm to a creature of significant threat (DM's discretion). You regain all your expended grit points when you finish a short or long rest.