Way of the gun

while most monks use there fist, or weapons that they specialize in, you discovered that guns, despite there limitations are really effective in combat, giving you range, while managing to keep up with, or dealing more damage than your fist or weapons. 

Gunweilder

when you obtain this subclass your unarmed attacks are replaced by a gun attack. they are now ranged(25/40ft.), and deal piercing damage. every time you attack you lose 1 bullet, every 6 shots you must use an action to reload 6 more bullets into your gun. You can choose to reload if you are before you run out of ammo and regain ammo in your gun until you hit 6 shots. 

3rd level

fast hands

you may now reload as a bonus action rather than an action.

when you successfully attack somebody you can choose to deal that damage to 2 people. this cannot be used when the hit is for an extra attack or martial arts attack. 

6th level

Unload

For your action you may choose to unload your clip into someone, dealing 1d12 damage for every shot left in your gun. if you critical fail the hit roll for this attack you take the damage instead. you may use this once per long rest. 

11th level

fastest hands in the multiverse

You no longer have to reload, and unload always does 6d12 damage.

17th level 

Improved range

your guns now have 40/70ft range 

17th level

obliterate

Once per long rest you may use all 6 bullets in your gun to instakill an enemy whos cr is 13 or less.

17th level