Next, I needed to create the projectile.

To match Rio’s barrel, we should standardize its specifications. Since we’d be firing it at that massive Sea Emperor Turtle, it needed to be a decent size. A diameter of about fifty centimeters should do. I also had to determine the width and depth of the rifling grooves.

“Got it. Let’s adjust things as we go.”

Ideally, we’d make different sizes, but for now, the priority was countering the Sea Emperor Turtle. I began crafting fifty-centimeter projectiles, ensuring the grooves were evenly spaced and smooth. With each attempt, the design gradually improved.

“Alright, I’m heading out. The Imperial Army has summoned me.”

“Ah, okay. Thank you for everything.”

Linford had other obligations and left in the evening. Since it was related to the Imperial Army, it was probably tied to his noble duties.

Meanwhile, Nir had nothing to do, so he was entertaining himself by hunting giant fish near the water’s surface. He’d leap out, strike the fish mid-air, and bring them over to us.

“Alright, this shape should work.”

“Got it. I’ll craft a barrel to match it.”

“I’m counting on you.”

“Leave it to me.”

For now, I set aside the concept of railgun mechanics and focused on getting the basic structure functional.

“Let me know if anything needs adjusting.”

“Will do.”

Next was refining the projectile itself. The best outcome would be adding impact penetration. …Now, how did I usually apply it when using my fists?

I pulled out my gauntlet and equipped it. Since it covered my fists entirely, the impact penetration effect must be traveling through the gauntlet to the target.

To test it, I applied the effect and punched the ground, shattering a thirty-centimeter-wide section into dust. That meant the gauntlet successfully transmitted the impact.

I removed the gauntlet and picked up the projectile I had just made. The goal was to imbue it with the same effect.

“Hmm…”

Wasn’t there a skill for attribute or effect imbuing? If there was, I’d love to learn it right about now. Come on, enhancement skills, do your thing.

I tried repeatedly—punching the ground barehanded, striking with my palm, slamming my hand against the projectile. Every time the projectile shattered, I remade it and kept going.

“…Oh?”

I suddenly felt something different.

This might actually work. Time for a test shot.

I used earth magic to create two targets, each about thirty centimeters thick, reinforcing them with magic to be extra durable. For the test, I’d use a thirty-millimeter projectile.

I prepared two projectiles—one with the impact penetration effect and one without. No rifling this time. The barrel was about fifty centimeters long. I compressed the air, loaded the projectiles, and moved ten meters away before taking aim.

When I fired, the first projectile made a light sound as it flew and embedded itself in the target, leaving a small hole but causing no other visible damage.

Then, I fired the second projectile.

A loud shockwave erupted upon impact.

“Whoa.”

Approaching the targets, the difference was clear. The second target’s back had been completely blown out, with only about five centimeters of the front remaining from the original thirty-centimeter thickness. This was fun. I should call it an "Impact Bullet."

As I admired the result, I heard a deep sound beside me.

It seemed Rio had fired the fifty-centimeter projectile I had made into the sea.

“At least it flies properly now,” she said with a bright smile.

The next morning, we resumed sniping magic practice.

Since I had successfully created the Impact Bullet yesterday, today’s goal was for Rio to fire it.

On the empty coastline, I created a ten-meter-wide, durable rectangular target.

“Here I go.”

“Alright, I’m counting on you.”

We moved about a kilometer away from the target, and Rio constructed a barrel over ten meters long. I set the Impact Bullet inside.

“Okay… Fire!”

A massive explosion echoed as the projectile was launched—but the target remained intact.

“…Huh?”

“…Something’s off.”

Apparently, the projectile had shattered from the launch’s force.

“Maybe we need to increase its durability.”

“Or the rifling might be uneven.”

“Let’s try reinforcing the projectile first. If the rifling still seems off, we’ll reconsider.”

Nodding in agreement, I began crafting stronger Impact Bullets while Rio refined the barrel and continued test-firing.

We still hadn’t implemented the railgun’s electromagnetic acceleration. There was also the option of using gravity magic to increase the projectile’s weight. Once the spell was nearly complete, we’d need to conduct practical tests in combat conditions. Since we’d be pouring in maximum magic power, we wouldn’t be able to fire it too many times a day.

“It’s taking longer than I expected… but we have no choice.”

As I gazed at the steadily approaching Sea Emperor Turtle from the shoreline, I muttered to myself.