Sharpshooter

These fighters have honed the art of long range combat using a firearm, but because they get bored easily, they decided to make a game out of the battle field. Trying to get the coolest trick shot with the biggest explosion. 360 no scope type of people

Firearm Specialist

At lvl 3, these fighters have gotten so used to using their firearms, that it feels like second nature to them. You gain proficiency with firearms and get to do a Quick Reload. A Quick Reload is a bonus action that reloads you firearm. The number of uses is 3 + your DEX modifier.

Opportunist

After looking for many ways of making your trick shots the best of the best you become an expert on scouting out location’s. This grants you expertise in Wisdom(Perception) throws.

“All I need is one shot”

Your need to always have the coolest shots in the world has made you learn to make the last shot count. You make your attack rolls at an advantage when you only have one shot left in the firearm.

Full Caliber Barrage

You have learned the ins and outs of your fire arm to the point that you know how to empty your entire weapon in a single action. You have learned the skill Full Caliber Barrage, the skill allows you to empty your entire magazine to deal all that damage in a single action, but you need to roll for DC every time and if you roll bellow a 10, your firearm jams and you'd need to reload it. You can only do this once per long rest. 

Bringing a Gun to a Sword fight

At lvl 7, you’ve become a master of the ranged vs melee match up, so much so that you roll your attack rolls with ranged weapons with advantage against creatures within 5ft away from you.

A Warning Shot

At lvl 10, you have mastered the art of drawing your weapon faster than everyone else around you, this allows you to fire off a Warning Shot at a target before everyone else gets ready for combat. Unfortunately, Full Caliber Barrage is to slow to be usable in this moment.

Blind Shot

At lvl 15,  you have gotten so good at trick shots and predicting where your target is going to be, that you’ve started to learn how to scout out the targets whereabouts without even being able to see them.

Force of Nature

At lvl 18, your skill with the firearms has gotten so godlike, that nothing can ignore your shots. Your attacks with firearms ignore the piercing sistances of your target.

“I like these odds”

At lvl 18, you have gotten used to getting outnumbered in fights. So much so, that now every single time the number of enemies outnumber the number of allies, you roll your attack rolls with firearms, DEX and initiative rolls with advantage.