Deadly Aim. When the gunsmith hits a humanoid or a beast with a musket or rifle, it rolls the weapon's piercing damage dice three times and uses the total.

Infused Weapons. The gunsmith's ranged weapon attacks using a musket or rifle are magical, and it uses its Intelligence modifier, instead of Dexterity, for the attack and damage rolls. When the gunsmith hits with a weapon attack using a musket or rifle, the weapon deals an extra 1d6 fire damage and 1d6 force damage (included in the attack).

Spellcasting. The gunsmith is a 15th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 17, +9 to hit with spell attacks). It has the following artificer spells prepared. It can use a musket, rifle, or smith's tools as an arcane focus for its spells.

Cantrips (at-will): create bonfire, mage hand, mending, ray of frost
1st level (4 slots): absorb elements, catapult, shield, thunderwave
2nd level (3 slots): cannon blast (new), scorching ray, shatter
3nd level (3 slots): fireball, lightning bolt, protection from energy
4th level (2 slots): fabricate, wall of fire

Multiattack. The gunsmith makes two rifle attacks. It can replace one of those attacks with casting a spell.

Rifle. Ranged Weapon Attack: +9 to hit, range 120/360 ft., one target. Hit: 12 (2d6 + 5) piercing damage plus 3 (1d6) fire damage and 3 (1d6) force damage.