Path of the Bombardier

For you who strikes with explosive rage, only explosive weapons will do.

Wrath of Firearms

3rd-level Path of the Bombardier feature

You have Proficiency with firearms, can use STR for attack & damage rolls & can add rage damage to your firearms.

Explosive Strike

6th-level Path of the Bombardier feature

You have a number of charges = to 1/2 your Barbarian Level. While you are raging, you can spend 1 charge to enhance your melee weapon attacks with explosive energy, 2 charges for range attacks. All creatures within 5 ft of where your attack lands make either a DEX or CON save (targets choice), taking 1d(2(STR MOD + 1)) fire damage on a failed save or half as much (rounded down) on success. If your STR MOD = 0 or less, add your STR MOD to the damage (min of 0). If your STR MOD is greater than 5, add your STR MOD - 5 to the damage. If the target of the attack was hit, the save they make must be CON & is made at disadvantage. DC = 8 + PB + your STR MOD. You regain all spent charges after a long rest.

Blast Back

10th-level Path of the Bombardier feature

Whenever a creature is hit by an attack under the effects of "Explosive Strike", that creature must make a STR save. On a failed save, the creature is knocked backed a number of feet = "Explosive Strike" DC - their save divided by 3 (rounded down) multiplied by 5ft.

Fragmentation

14th-level Path of the Bombardier feature 

If the attack that utilizes "Explosive Strike" fails to hit a creature, any creature caught in "Explosive Strike" takes piercing damage = to your rage damage bonus.