Cannonballer

Weapon

Common

AP, Breech (12 shots), Direct (2d6+6), EXP (5 ft.), Heavy

D&D Firearm Rules

Check Weapon Properties & Groups for AP, Breech, Direct, EXP & Heavy properties

Instead of launching a rocket or a mine, the cannonballer fires out a short-range explosive sphere.
Although it can direct hit and detonate like a grenade or detonate nearby and inflicting damage via an area effect, you can also direct it to roll around the ground under its own power until finding a target.

Bouncer (3rd level).
If you do not directly hit with this weapon, you can elect to have it land without detonation. When on the ground, it gains a movement of 30, and as a bonus action, you can direct it to move. Detonation only takes an action, but you can no longer inflict direct damage.
You can only move a ball once per turn and you can only control one ball at a time.
A ball has an AC of 18 and 1 hit point, and if struck, it explodes at its location.
A ball can be controlled for up to one minute before it runs out of power and turns itself off. It can still be detonated, but it cannot move.