It is easier to polish the outer wall of the gun barrel, but to polish the inner chamber, special tools must be provided, such as a hand-crank grinder. Li Laoer guided the blacksmith and carpenter to build a hand-crank grinder.

Like hand-crank blowers, they rely on pulleys and gears to change the transmission ratio. In order to increase the wear resistance of the gears, the transmission gears of the hand-crank grinder are cast with iron. Li Laoer directly made a sand mold for casting gears and poured the molten iron into it. Because the blast furnace temperature is high, when the pig iron melts, the carbon in the pig iron is burned out. After cooling, it becomes a high-purity cooked iron.

Although the quality of this kind of cooked iron is not as good as that of the fine iron produced by the blacksmith shop after repeated trials, it is enough to cast cannons and parts. If this kind of cooked iron is tempered by the blacksmith, it can obtain high-quality fine steel.

Li Laoer's own horse spear and fine steel armor-breaking cone are the fine steel obtained by making the hard iron after being tempered. This method can also create the spring steel needed for the flintlock machine, but the output is too low, because the fine steel that is beaten may be a good material for making weapons, but it may not be able to become high-quality spring steel.

Under the command of Li Laoer, the craftsmen installed the cast gears according to the drawings and applied animal grease to reduce friction.

After the last handle is installed, a hand-crank grinder is ready.

A craftsman tried to shake the handle gently, and a iron rod in front turned rapidly under the gears.

With a grinder, you must consider making abrasive tools. Li Laoer asked someone to polish the gray sticky sandstone used to make whetstone into a cylindrical shape, dig a hole in the middle, put the whetstone into a cylindrical shape into the iron rod of the grinder and fix it. This way a hand-crank grinder is done.

"Grind the outer wall first, and after it is ground, take it to use a grinder to polish the inner wall." Li Laoer ordered the craftsman.

Two craftsmen were holding a whetstone in their hands and polished the outer wall of the gun barrel to remove the burrs and sand particles from the outer wall. However, after all, it was not polishing the inner wall. It didn't need to be particularly smooth, as long as it could be passed.

The gun barrel that had polished the outer wall was sent to the workbench of the grinder. The workbench was suspended in mid-air with a hand-crank. Two craftsmen clamped the gun barrel with a hand-crank fixture. Then a craftsman put the abrasive tool into the inner wall of the gun barrel and slowly shook the handle of the hand-crank grinder. The abrasive tool quickly rotated on the inner wall of the gun barrel. The other two craftsmen kept adjusting the workbench to ensure that each side of the inner wall of the gun barrel could be ground. After about a cup of tea, Li Laoer shouted: "Stop!"

The craftsman quickly stopped shaking. The two craftsmen loosened the clamp and lifted the gun barrel off the workbench. Then they poured water into the gun barrel and cleaned the iron filings. The barrel chamber was completed.

"It's so smooth inside! It's grinding like a mirror!" A craftsman reached into the cannon barrel and touched it.

If the gun barrel is built well, a gun mount needs to be built. Only with the gun mount can it be considered to be truly completed.

The artillery mount of the Ming army artillery was a simple wooden rack, placed on the ground, and the cannon was placed on it. The artillery mount of the chariot camp was placed directly on the car, because the cannon was light in weight and could be fired on the car.

It is precisely because the Ming army's artillery mounts were backward that the heavy red barbarian cannons and general cannons were very complicated from transporting to mounting guns. During the transportation process, the cannons were separated from the cannon stand and transported by ox carts. After being transported, the cannon stands on the ground, then the cannon barrels were taken off the ox carts and placed on the cannon stands.

That is, the artillery mounts are behind, so it is impossible for the chariot camp to be equipped with real medium-sized artillery. In the entire Ming army's artillery system, except for heavy artillery over a thousand kilograms, there are light artillery less than 100 kilograms, and medium-sized artillery ranging from three to four hundred kilograms to five to six hundred kilograms.

The cannon mount that Li Laoer wanted to build was a copy of later Western-style field artillery carts.

The field gun carriage is a gun mount made of elastic wood, which is placed on the axle, with two large wheels, which are somewhat similar to the carriage, but have no carriage. The wooden gun mount is made of ash with very elasticity. One end of the gun mount is placed on the axle, and the end is two thick beams, which can be placed on the ground. The tail of the gun is a thick wooden board with a hole drilled on it.

Li Laoer also asked someone to build another ammunition truck that was specially connected to the gun van. The ammunition truck is also a two-wheeled truck, which is somewhat like a carriage. There is a protruding wooden board in front and a hole is drilled on it, which can be hung together with the rear of the gun van.

When the field gun marching, lift the tail of the gun, aim the hole of the thick wooden board at the connection of the ammunition truck, insert it with an iron bolt, and fix it. The two cars will form a four-wheeled car.

When you arrive at your destination and need to fire, unload the ammunition truck and pull it aside. Place the tail of the gun truck on the ground and load the shells and then fire it.

Building artillery and ammunition trucks is also a complex process. It requires finding expensive ash wood and processing the wood accordingly. After all, it is a long-term use thing. Unlike disposable siege weapons, the wood needs to be treated with anti-corrosion and deformation prevention before it can be used after treatment.

Before the cannon cart and gun mount were built, Sun Chengzong couldn't wait to see the shooting effect of this cannon.

The craftsmen worked overtime and cast ten solid shells and five shrapnel shells according to Li Laoer's design drawings. These shells were fixed behind the shells with cork support. The production of shrapnel shells was more complicated. The shell shell shell was a hollow ball made of thin iron sheet, with hundreds of iron beads inside, and a vent hole was left behind. A vent hole was also drilled on the cork support, which could allow gunpowder gas to pour into the inside of the bullet body.

Sun Chengzong asked the special agent to temporarily replace the field artillery mount with the artillery mount of the general's artillery and began to test the new artillery.

Three hundred steps away, a piece of Sancun-thick wooden board with cowhide and iron sheets on it was completely a wooden target made of the shield of the rear gold shield car.

Li Laoer took the craftsman and loaded the cannon himself. He stuffed a fixed charge pack into the muzzle, and then stuffed a solid shell with a cork mount into the muzzle to the muzzle to solidify it. Then he walked behind the cannon, inserted an iron cone from the fire door, pierced the medicine pack, and inserted the fuse.

"Your Majesty, the loading has been completed and you can test the shooting." Li Laoer bowed to Sun Chengzong.

"Let's go."

Li Laoer lit the cannon himself, and only a dull roar was heard. Fire light spurted out from the fire gate and muzzle, and white smoke rose from the muzzle. A cannonball roared out, accurately hitting the wooden target three hundred steps away.

Sun Chengzong was originally staring at the cannon. When he heard the sound of cannons, he immediately looked up at the wooden target in the distance. The shells hit the wooden target fiercely. The entire wooden target immediately flew backwards more than ten steps away. All the wooden boards behind the wooden rake turned into pieces, leaving only an empty cowhide and a distorted iron sheet in front.

"What a great power!" Sun Chengzong touched his beard and said, "General Li, this cannon is so powerful, what name should be given?"
Chapter completed!