Let the delicate elves hide amongst the trees with their longbows! You take a different approach. Dwarven tradition places artillery in the front ranks where they can get up close and personal with the enemy. Using a variety of custom-crafted ammunition (often with explosive results), these fighters are hard to ignore at any range.

Artillery Specialist

3rd-level Heavy Artillery feature

You have learned how to create your own weapon and ammunition. You gain proficiency with Tinker’s Tools and Smith's Tools if you don't already have it.

Over the course of a long rest, you can use Tinker's Tools, Smith's Tools, and 25gp of metal scrap to create a personal cannon. Over the course of 1 hour, which can be done over a short rest, you can use Tinker's Tools, Smith's Tools, and 5gp of metal scrap to create 30 shells of ammunition.

Additionally, you learn to craft special ammunition with powerful effects. When you gain this feature, you learn two Tactical Munitions options of your choice (see “Tactical Munitions Options” below). During a short or long rest, you can craft shells of each type of Tactical Munitions you know. Once per turn when you make an attack with your personal cannon, you can use one of your Tactical Munitions shells as ammunition. These powerful shells take a toll on your cannon, and once you have fired two Tactical Munitions shells you must clean and maintain your cannon over a short or long rest before you can use this feature again. At the end of the rest you regain two uses of the Tactical Munitions options.

You gain an additional Tactical Munitions option of your choice when you reach certain levels in this class: 7th, 10th, 15th, and 18th level. Each option also improves at 10th and 18th level.

Personal Cannon

3rd-level Heavy Artillery feature

You gain proficiency with a 25-pound portable cannon, which makes a ranged attack called Heavy Shot. The personal cannon is a martial ranged weapon with the ammunition, heavy, loading, and two-handed properties. It has a normal range of 30 feet and a long range of 60 feet, and on a hit it deals 1d10 bludgeoning damage. Unlike other ranged weapons, you use your Strength ability modifier to determine attack and damage values, and you can ignore the disadvantage penalty for making ranged attacks when an enemy is within 5 feet. As a bonus action, you can load up to 3 shells into your personal cannon, which fires one shell per attack.

The cannon is not designed for making melee attacks, but it can be used to do so in accordance with the rules on improvised weapons.

Using Personal Cannons in D&D Beyond

Unfortunately the D&D Beyond homebrew system doesn't currently support custom weapons. Your cannon's Heavy Shot attack is attached to this class regardless of your equipment, but you will need to add a cannon to your inventory manually. I suggest modifying the name and weight of a heavy crossbow.

Through the course of your adventures you may find powerful magical cannons crafted by long gone heroes, or perhaps you may craft one of your own. When such an item includes additional bonuses to attack and damage, you will need to customize the Heavy Shot action on your character sheet in order to include them.

Ricochet Shot

7th-level Heavy Artillery feature

You learn how to direct errant ammunition toward a new target. When you make an attack roll with magic munitions and miss all targets, you can use a bonus action to reroll the attack roll against a different target within 30 feet of the original target.

Magic Munitions

7th-level Heavy Artillery feature

You gain the ability to infuse your ammunition with magic to create shells which load themselves as a part of your attacks without any actions required from you. You can ignore the loading property on your personal cannon, and the shells (including all Tactical Munitions) count as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage. The magic fades from the shells immediately after they hit or miss their target.

You can also make a 3rd type of Tactical Munitions.

Advanced Munitions

10th-level Heavy Artillery feature

You can now make 4 different types of Tactical Munitions, and each type becomes more potent (see munition descriptions for details).

Additionally, all shots fired from your personal cannon deal double damage to objects and structures.

Emergency Maintenence

15th-level Heavy Artillery feature

With a few improvised repairs, you can hold your cannon together in a pinch. If you roll initiative and have no uses of Tactical Munitions remaining, you regain one use of the feature.

You can also make a 5th type of Tactical Munitions.

Superior Munitions

18th-level Heavy Artillery feature

You can now make 6 different types of Tactical Munitions, and each type becomes more potent (see munition descriptions for details).

Additionally, all shots fired from your personal cannon deal triple damage to objects and structures.

Tactical Munitions

The Tactical Munitions features are presented below in alphabetical order. If an option requires a saving throw, your Tactical Munitions save DC equals 8 + your proficiency bonus + your Strength modifier.

Concussive Shell

When you hit a creature within 30 feet with this shell, it takes force damage equal to Heavy Shot plus an extra 2d6 force damage and it can't take reactions until the end of its next turn. Any concentration checks made as a result of this damage are made at disadvantage.

The extra force damage increases to 3d6 when you reach 10th level in this class and 4d6 when you reach 18th level in this class.

Container Shell

Once you have crafted this hollow shell, you can use a bonus action to place inside one non-magical item that weighs 3 pounds or less.

This shell can be fired at a creature or object within 30 feet. On a hit, the target takes Heavy Shot damage and is also considered to be hit by any attacks or effects that are possessed by the included item. If the item has an effect requiring a saving throw, you can replace the DC with your Tactical Munitions DC. On a miss, the shell remains intact and can be recovered after the battle.

At 10th level in this class, you can add an additional 1d6 to any damage dealt by an included item, and at 18th level in this class, this additional damage increases to 2d6.

Firespew Shell

This thin, hollow shell is filled with incendiary liquid. On impact at a point you target within 30 feet, the shell releases a wave of fire originating from the target in a 15 foot cone spreading in the direction of the initial shot. The target and each creature in the cone must make a Dexterity saving throw, taking 2d8 fire damage on a failure or half as much on a success. 

At 10th level in this class, the affected area becomes a 30 foot cone and the fire damage increases to 3d8. The fire damage increases to 4d8 when you reach 18th level in this class.

Grappling Shell

When attacking with this shell, you can attach one end of its rope to yourself. You then fire at a creature, object, or solid surface within 50 feet. If fired beyond that distance, the shell quickly loses momentum and falls to the ground.

If the target is a creature and the attack hits, the target takes Heavy Shot damage and becomes affixed to the rope. While you and the target are connected by the rope, you can both move freely but you cannot be farther apart than the maximum length of the rope, although you can drag each other up to half the dragger's movement speed with a successful contested Strength (Athletics) check. As a bonus action, you can tie off the rope to set its maximum length to your current distance apart. To remove the rope, the target must use an action to make a Strength saving throw against your Tactical Munitions DC. On a success, the rope becomes detached and falls to the ground.

Alternately if the target is an object or a solid surface, the shell lodges itself firmly in place at the point of impact. The attached rope can support up to 600 pounds of weight before detaching from the shell. Ropes woven from special materials may be able to support greater weight.

Crafting this shell requires a 50-foot length of rope. The adhesive attaching the rope to the shell disintegrates 1 minute after the shell is fired, and at that point the rope can be recovered.

At 10th level in this class, you can use a bonus action to attach your end of the rope to an adjacent object or willing creature before firing the shell. At 18th level in this class, the target has disadvantage on Strength checks and saving throws related to this feature.

Hobbling Shell

When you hit a creature within 30 feet with this shell, spiked chains wrap around it. The target takes Heavy Shot damage plus an extra 2d6 slashing damage, its speed is reduced by 10 feet, and it takes 2d6 slashing damage the first time on each turn it moves 1 foot or more without teleporting. The target or any creature that can reach it can use its action to remove the chains with a successful Strength (Athletics) check against your Tactical Munitions save DC. Otherwise, the chains last for 1 minute or until you use this option again.

Both instances of slashing damage increase to 3d6 when you reach 10th level in this class and 4d6 when you reach 18th level in this class.

Impact Shell

A creature within 30 feet hit by the shell takes Heavy Shot damage plus an extra 2d6 bludgeoning damage, and it must succeed on a Strength saving throw or be knocked prone and pushed up to 10 feet.

At 10th level in this class, the bludgeoning damage increases to 3d6 and the push increases to 15 feet, and at 18th level in this class the bludgeoning damage increases to 4d6 and the push increases to 20 feet.

Piercing Shell

This shell shoots forward in a line 1 foot wide and 30 feet long, passing through objects and ignoring cover. Each creature in the line must make a Dexterity saving throw. On a failed save, a creature takes piercing damage equal to Heavy Shot, plus an extra 1d6 piercing damage. On a successful save, a target takes half as much damage.

At 10th level in this class, the line extends to 60 feet and the extra piercing damage increases to 2d6. The extra piercing damage increases to 3d6 when you reach 18th level in this class.

Prismatic Flare

When you make an attack with this shell, multicolored sparks stream out from your cannon in a line 5 feet wide and 30 feet long. A creature that starts its turn in the area must succeed on a Constitution saving throw or take 2d6 radiant damage. Creatures with darkvision have disadvantage on this saving throw. The area within the line is illuminated with bright light, and dim light extends 30 feet out from it.

This effect continues for one minute. During this time you cannot make ranged attacks with your cannon, but you can take an action on your turn to reposition the line of sparks.

When used in an open area around non-hostile creatures, the colorful spectacle draws attention. Non-hostile creatures within 60 feet of the effect have disadvantage on Perception checks while the sparks are visible.

Starting at level 10 in this class, the radiant damage increases to 3d6 and you and your allies have advantage on Charisma checks on non-hostile creatures who can see the effect. Starting at level 18 in this class, the radiant damage increases to 4d6 and creatures that fail the saving throw are also blinded until the start of their next turn.

Shrapnel Shell

This shell breaks into several pieces when it is fired, affecting creatures in a 15 foot cone originating from your position. Each creature in the area must make a Dexterity saving throw. On a failed save, the creature takes Heavy Shot damage plus an additional 1d6 piercing damage. On a successful save, the creature takes half as much damage.

The affected area increases to 30 feet at 10th level in this class and the additional piercing damage increases to 2d6 when you reach 18th level in this class.

Thunderblast Shell

When fired at a point within 30 feet, this shell detonates in a blast with a radius of 10 feet. Each creature within the affected area must make a Constitution saving throw. On a failure, the target takes 2d8 thunder damage and is deafened for one minute. On a successful save, the target takes half as much damage and is not deafened.

At 10th level in this class, the blast radius increases to 15 feet and the thunder damage increases to 3d8. At 18th level in this class, the thunder damage increases to 4d8.