At1st level, you gain proficiency with rifles and gain the spellcannon - a magic item that only you can attune to. While you are attuned to it and wielding it, you may use the attack action to make a ranged weapon attack with the spellcannon. Roll a d20 and add both your proficiency bonus and spellcasting modifier. On a successful hit the target suffers 1d12 force damage.

The gun is a rifle with a range of 100/400. After making an attack with this weapon, it must be reloaded before it can be used again. You can reaload your spellcannon by using a bonus action on your turn. This weapon has the loadingproperty and counts as magical for the purpose of overcoming resistance and immunity to non-magical attacks and damage.

You can create a new gun at the end of a long rest by touching a non-magical heavy crossbow, which magically transforms into it. Doing so removes the magic from your previous spellcannon, turning it into a non-magical heavy crossbow.

Starting at 1st level, you learn to channel magic through your spellcannon to augment your attacks in a variety of ways. When you make a ranged attack with your spellcannon, you can expend a spell slot of 1st, 2nd, or 3rd level to alter your attack. This may only be done once per turn. The effect depends on the spell slot you expend.

A 1st-level slot allows you to manipulate the bullet’s energy. You can substitute the damage type for another one from the following list: acid, cold, fire, lighting, or thunder damage.

A 2nd-level slot magically steadys your spellcannon's aim, gaining you advanatge on the attack roll.

A 3rd-level slot imbues the bullet with a powerful arcane blast. Each creature in a 10-foot-radius sphere centered on the bullet’s point-of-contact must make a Dexterity saving throw or suffer 6d6 force damage, halved on a success. Creatures that fail the saving throw are knocked prone.