Magic (which is just ancient technology and not supernatural mumbo jumbo) in this setting is close to what you'd find in the anime Grimoire of Zero. That is to say it has a set of rules and the list of spells is grouped by function and the elemental aspect is missing entirely.
The spell we talk about today is a magical bow (called steim in the show) that shoots an explosive projectile.
I my world, it's called
Magical artillery, at its core, uses swarms of micro machines, that are designed to explode upon contact with the target. They're about as fast as an average arrow, but are able to recognize objects and change direction. They're also able to break up into smaller pieces and reassemble later.
The power of a single shot can be turned up or down. The more powerful a shot is, the bigger (usually in length) it gets.
The primary weakness is the fact that a shot can be prematurely detonated by the enemy.
This is all fine, bit the main reason why there are only a handful of rifles and cannons in the setting is because Magical artillery is comically better than them, plus there are spells that can jam or even destroy ordinary guns, I think its name was "/k/ry of the Second Amendment ".
However, I doubt that Magical artillery in its current form would be able to out conventional ranged weaponry. I'd like to know, what property this spell needs to have to be able to outperform conventional assault rifles, rifles and machine guns?
Note: I'm not sure if the weapon classifies as artillery