Gun, the weapon of freedom

With the wedding scheduled in a month's time, and with that, Meiyue's departure to return with the trader back to Rajput, the development of the weapon is being increased at higher pace. A week later, you, Meiyue, Vikram, and few people you trusted went to a field away from the palace. While you could have used the archery range in the castle, doing so would only leak the weapon's existence to spies inside the castle.

A protoype 'Gunnhild' or as you suggested, 'gun', is placed on a table. It is a crude, heavy thing, cast from bronze with a bulbous breech and a flared muzzle, looking more like a small, elongated vase than a weapon of war. The royal blacksmith stood back, wiping sweat from his brow. Designing and making a gun is the easy part; ensuring it wouldn't explore is the difficult part. A thick iron bolt, wrapped in leather to create a tight seal, was rammed down the throat of the bronze cylinder.

You look at the powder on the table. "That's the powder?"

"Saltpeter," Vikram said. "Can cure meat, and apparently cause flames to burn brighter. Made from the best guano."

Meiyue mixed the poweder, explaining that not only the ingredients are important, but the ratio and the mixing processWith the steady hand of an artist, she began to mix them, explaining to the King that the secret lay not just in the ingredients, but in the processing as well. She then load the bullet and the powder into the gun, and then after some more adjustment, raise to aim the weapon at an armor mounted on a wooden post fifty paces away.

There's a loud bang, causing you to instinctively blink and cover your ears.

A large plume of smoke exits the weapon. Meiyue lowers the weapon and gestures to the armor. When all of you get to the said piece, you can see a thumb-sized hole punched clean through the breastplate. You run your finger over the hole, realizing that the era of the mounted knight and the impenetrable castle wall had just begun its slow, thundering decline. You look at Meiyue, and then at her future husband. "You have recreated the weapon from your state."

"No," Meiyue says. "It's a new weapon."