Ancient Enchanted 30mm Autocannon

Walking into the dark storage locker, the Apprentice Artificer slammed her shin into something hard. Cursing loudly, she turned to see what she "found" with her shin. Seeing a canvas tarp with "SECRET" stenciled onto it, she lifted it up to reveal a much smaller cannon than the one they were testing on the firing range. It was in pristine condition and appeared to be heavily modified compared to the larger cannon. Looking back she saw the Master Artificer give her a shushing motion then point to the Auditor who was roaming the facility. Nodding she covered the cannon and limped out with the new prototype charge she had made for her graduation exam.

This autocannon seems to be modeled after the Ancient 130mm Canon with fully automatic firing modifications.

Magic Weapon: Like its larger counterpart, the autocannon is enchanted to give advantages against misfires and cannot be consumed by a rust monster. Once a day if you roll a Nat 1 for an attack roll, the autocannon will not misfire. This autocannon is Approximately 10 foot long.

Safety First: The autocannon must be attached to a base or tank turret to be fired safely. If the user attempts to hip fire the autocannon without the prerequisite mounting methods or a 20 Strength, all rolls to hit are made at disadvantage. Unless the user has a strength of 20 or higher, the user must make a DC20 Strength save or take 3d6 bludgeoning damage, if save is made user still takes half damage. If not wearing hearing protection, anyone within 30 feet of the autocannon must make a DC15 CON save or be deafened for 2d4 rounds. The only way to safely hip fire this weapon without a 20 strength or disadvantage is if the Reduce spell is used on the autocannon.

Ammunition

• Enchanted Armor Piercing Charge:
  Armor Piercing Charges are magically treated to cause the highest piercing damage and destructive penetration Ancient Artificers could muster.

• Enchanted High Explosive Incendiary Charge:
  High Explosive Incendiary Charges are an Ancient Artificer design based on both of the Wizard spells Fireball and Fire Bolt.

• Enchanted Shrapnel Burst Charge:
  Shrapnel Burst Charges are a specialized munition utilizing an aerial burst that releases a cloud of sub-projectiles just ahead of a target.

• Enchanted Master Artificer's Piercing Charge:
  Master Artificer's Piercing Charges are a newly designed Charge created by the Master Artificer as a cumulative display for their benefactors. It has been created to combine the destructive technology learned from the Ancient 130mm cannon and intuitive technology also found at this ancient facility.

Players can craft all Charges or take found Charges to an artificer to have blueprints made. Armor Piercing Charges are roughly 50 GP per Charge, High Explosive Incendiary Charges are roughly 100 GP per Charge, Shrapnel Burst Charges are roughly 150 GP per Charge, and Master Artificer's Piercing Charges are roughly 200 GP per Charge if purchased at an artificer's shop. An artificer not currently furnished with a blueprint cannot make a Charge unless they have made one prior. If repeating shot is applied to this cannon it will fire whatever Charge variant was fired through it last.

If you want to find these Charge types in the homebrew magic item listings, look to the comments below. Each Charge has been attributed to an "Arrow" as to track it in player inventories.

It’s up to you to decide whether a character has proficiency with a firearm. Characters in most D&D worlds wouldn’t have such proficiency. During their downtime, characters can use the training rules in the Player’s Handbook to acquire proficiency, assuming that they have enough ammunition to keep the weapons working while mastering their use.

Notes: Damage: Piercing, This cannon is roughly 10 feet long. The Charges are 30x173mm., Damage, Social, Range, Two-Handed, Ammunition (Firearms), Burst Fire, Reload, Slow