High Fantasy Firearm

Just wanted to share an idea I had for how firearms could function in a world with magic. Feel free to take the idea if you want - I couldn't stop you regardless - or offer some criticisms or ways to improve the concept.

I'm currently running a DnD campaign and I've decided to introduce firearms into my world. They are still new to the world, and resemble flintlocks. I'm currently calling them Runework guns, though I am trying to figure out a name I like more.

Basically, the way they work is mostly similar to any flintlock gun. You load the "dragon salt" and lead ball down the barrel into a chamber at the base of said barrel. The opposite side of the wall of the chamber that the salt is packed in against has half of a flame rune etched into it. When you pull the trigger, a second piece of metal with the other half is pressed against the first piece in a way that completes the rune, instantly super heating the metal, igniting the explosive dragon salt, and propelling the lead ball out of barrel.

It's functionally identical to a flintlock gun, but with just a little twist to make it feel more magical. What do you think?