Li Dao Xuan looked at Bai Yuan's frustrated expression and could not help but chuckle inwardly.
So the pursuit of precision has already begun.
That was inevitable.
After the invention of fire muskets, countless craftsmen and weapon innovators had been chasing accuracy for generations. The evolution from the three-eyed fire lance to the arquebus itself was already an early attempt at improving precision. At that time, craftsmen tried to extend the barrel length, hoping that a longer barrel would stabilize the projectile's exit trajectory and make the shot more accurate.
But smoothbore muskets, no matter how refined, were ultimately a joke when it came to true accuracy.
Because the barrel was smooth inside.
Once the bullet left the muzzle, it would spin, wobble, and fly wherever physics felt like sending it. No one could control that chaos.
If one truly wanted a stable forward trajectory, there was only one solution.
Rifling.
Rifling was not some high-level divine invention. As early as 1498, craftsmen in Germany had already developed rifled barrels. And now it was the second year of Chongzhen, which meant it was already 1629, more than a hundred years later. With the craftsmanship of the Ming dynasty, rifling was absolutely achievable.
The only issue was that hand-cutting rifling grooves required extreme precision and was painfully time-consuming. Mass production was difficult.
But since the technology threshold was already within reach, Li Dao Xuan saw no reason to hesitate.
Just give it.
He pulled out the prepared technical documents on rifling and casually dropped them down like a heavenly gift.
What he provided was the simpler version, straight rifling grooves rather than spiral ones. A step-by-step approach made things easier for humans below.
Bai Yuan was still holding his modified flintlock arquebus, aiming at a flying bird in the sky.
Left aim, right aim, adjust again.
Nothing felt right.
He sighed in frustration and fired casually.
Bang.
At the exact same moment, the paper Li Dao Xuan had dropped floated down through the air.
The bullet struck it perfectly.
Right through the center.
The paper instantly had a clean hole punched through it.
Bai Yuan froze for a second, then his face changed dramatically.
"Oh no, I have struck the Heavenly Scripture bestowed by Dao Xuan Tianzun."
The paper drifted down slowly and landed right in front of him.
Bai Yuan carefully looked at it.
It was a technical diagram explaining how to improve firearm accuracy.
But the most critical section, the rifling diagram, had been shot clean through. The central part was missing, leaving the cross-section completely unreadable.
For a moment, silence.
Then panic exploded.
"Aaaaaah."
Bai Yuan screamed.
"It is over, it is all over. I have damaged the Heavenly Scripture bestowed by Dao Xuan Tianzun to improve firearms accuracy. Heaven help me, I have destroyed divine knowledge. Aaaaaah."
Thud.
He collapsed onto the ground dramatically.
The surrounding servants rushed forward immediately and helped him up.
Bai Yuan looked devastated.
"I do not even know how to atone for this. The virtue of ritual and propriety, remove it, remove it from the list."
Li Dao Xuan laughed out loud above them and simply printed another copy.
Then he dropped it down again.
Bai Yuan immediately perked up.
"So there is a second copy of the Heavenly Scripture. So destroying one is not a problem."
His despair vanished instantly, replaced by eager excitement.
He carefully unfolded the massive sheet of paper and climbed up a nearby tree to get a better viewing angle.
He stared for a long time.
Then he frowned.
He did not fully understand it.
The truth was simple.
Bai Yuan had only learned mathematics so far. He had not yet studied physics or chemistry. Many subtle principles simply could not be understood without those foundations.
But it did not matter.
If he could not understand it, he would just take the document with him.
He immediately ordered his servants.
Roll it up.
Then they rushed toward the train station carrying the enormous paper scroll.
When the next train arrived, they shoved the rolled "Heavenly Scripture" into the carriage and boarded it themselves.
The train chugged forward with a rhythmic clattering sound, heading toward Gao Village School.
The Gao Village school had become increasingly surreal.
A five story teaching building stood beside a massive microscope installation. Students would climb up to the fifth floor using a prebuilt scaffolding system, then peer downward through the microscope apparatus from above. Meanwhile, students on the second floor would place specimens onto elevated trays aligned with the viewing system.
Everything in the school was oversized, industrial, and borderline absurd.
There were large experimental devices everywhere, arranged directly beside the teaching building so students could climb and use them easily.
These massive educational tools greatly accelerated the students' understanding of physics and deepened their grasp of scientific principles.
But Bai Yuan was not interested in any of that.
Anything not part of the Six Arts of a Gentleman was irrelevant to him.
He rushed straight into the school building and headed directly for the library.
Inside, Song Yingxing and Bai Gongzi were casually reading and discussing books.
Bai Yuan waved at the servants behind him.
"Bring in the Heavenly Scripture immediately."
The giant paper was unfolded in front of Song Yingxing and Bai Gongzi.
Bai Gongzi took one look and immediately understood.
"I see. I see now."
Bai Yuan already knew he could not compete with his son in physics. That subject was not part of the Six Arts anyway, so he did not care at all. He laughed and asked casually.
"What does this Heavenly Scripture mean?"
Bai Gongzi pointed at the rifling diagram.
"This is a structure used to stabilize the bullet. Lead bullets are soft. When fired, they deform slightly. The deformed part fits into the grooves of the rifling. This prevents the bullet from bouncing randomly inside the barrel."
He paused, then continued.
"It is similar to how train wheels follow rails. The bullet follows the grooves, maintaining a stable trajectory."
Song Yingxing nodded beside him.
"Yes, that is clearly how it works. Bai Gongzi's understanding of physics is truly excellent."
Bai Yuan became excited.
"So if we engrave these rifling grooves into the barrel, the bullet will fly straight and hit wherever we aim?"
Both of them nodded.
"Yes."
Bai Yuan immediately asked again.
"Then how do we make it?"
Song Yingxing pointed at the paper.
"It is written here. First, heat the barrel until it is red hot. Then use a specially made cutting tool and pull it through the inside of the barrel. The rifling will form this way."
He tapped the diagram.
"The hardest part is maintaining steady and uniform force while pulling. If the groove is uneven, the bullet will not fly straight."
Bai Gongzi chuckled.
"So it is best not to do it by hand. Human hands are too unstable. Even if it looks straight to the eye, under magnification it is already crooked. We have observed this many times under the microscope."
Song Yingxing added.
"So we can build a wooden machine, like a weaving loom. A straight rail system. Mount the cutting tool onto the rail so it stays stable. That way, we can carve perfectly straight rifling grooves."
The two of them quickly brainstormed together.
Within minutes, they had already designed a complete and practical production method.
Bai Yuan stood there listening, slightly dazed.
He did not understand most of the technical discussion.
But he understood one thing very clearly.
This thing called rifling could be made.
Very soon.
He suddenly became delighted and slapped Bai Gongzi on the shoulder.
"Hahahaha, not bad. You are becoming useful now. Very good. When I grow old, handing Bai Family Fort over to you might not be a problem after all. Hahaha."
Footnotes & Trivia
[1] Rifling Before the Ming
Straight rifling existed in Europe by the late 15th century. Spiral rifling came later and offered better stability but was vastly harder to produce. Early straight grooves already represented a massive leap over smoothbores.
[2] Why Rifling Works (In Plain Terms)
A deformed lead bullet gripping grooves reduces random tumbling. Even without spin, consistent guidance dramatically improves accuracy—an insight often rediscovered independently across cultures.