"Boss, I think this barrel should be made of bronze." Da Niu studied the drawings for a long time and said suddenly.

"You see, although this iron is hard, the hardness is not very useful, but the soft one is better than the shell."

"You see this copper is different, the melting point is low, the ductility is good, it is easy to cast and easy to adapt."

"We can completely replace the barrel with bronze, and these seven iron hoops are fixed with fine iron."

"The hardness of the barrel made of fine iron allows us to make the barrel longer, shoot farther, and be more accurate. However, an excessively thin barrel may make the charge of gunpowder smaller, which in turn will affect the design. ”

"Bronze is soft, and the barrel is shorter, but the barrel is thicker. Although the distance is a little closer, the reload is more sufficient. ”

"Personally, I still prefer short, thick and soft barrels, slender and hard are really useless." Da Niu took the drawings and expressed his opinions endlessly.

Although you have a lot of point, I still feel like you're driving. In order to prevent the big bull from driving the car directly overturned, Li Chen hurriedly interrupted him and said: "This matter will be handed over to you, I have only one request, that is, this cannon must be able to fire." ”

"Boss, don't worry, since I help you shoot, I will definitely use eighteen points of strength." Da Niu said seriously.

"It's to build a cannon, are you renting your tongue, it's not good to use." Li Chen scolded.

Although Da Niu has never read a book, he is definitely a genius in terms of craftsmanship. After a few days, Da Niu was not in a hurry to make a cannon. Instead, the casting method described on the drawings has been technically improved, and it is hard to imagine that a person as rough as a cow could write and draw calmly.

The main structure of this cannon is the barrel, which was usually made by casting in ancient times.

"Bang, bang, bang."

There was a thunderclap in the workshop, and under the leadership of Da Niu, the skilled craftsmen of the Damo Academy began to work together to cast the first cannon of the Great Qin, which would become the backbone of the old Qin people. In a few years, all artillery fire within range will be filled with the truth of Great Qin.

Some craftsmen first use very dry nanmu to make gun molds according to the style of the cannon body. The two ends of the gun mold should grow more than a foot to make a shaft head, and an iron swivel stick is added to the shaft head, and then the gun mold is placed on the rotating frame in order to rotate the mud.

After the gun mold is made, then the gun lug, the gun hoop, the mold with the word flower head is installed, and the gun mold is evenly painted with the coal ash that has been finely brushed, and then the good glue yellow mud and the sifted fine sand are used after drying, and the two eight phases are mixed to make mud, and the wool is shaken open, mixed into the mud, and evenly made "warp".

After the mud is adjusted, paste it on the gun mold, then turn the swivel stick, use a round mouth wooden swing board, dip it in water and wait for drying. After drying, apply the mud again according to the previous method. After the mud reaches a certain thickness, use a thick iron wire to wrap it from the head to the tail of the gun mold, and then apply the mud according to the method just now. When the required thickness is almost reached, the iron bar with a large finger is used to compare the length of the gun mold, the long one is used more, and the short one is used less, and it is evenly placed on the gun mold as a skeleton. Then, an iron hoop 1 inch wide and 5 minutes thick was used to evenly tie the iron bar from the head to the tail of the gun mold.

Then put on the mud and swing evenly. After it is completely dry, the wooden core is taken out and the charcoal fire is put into the clay mold, on the one hand, to burn the clay mold, and on the other hand, to burn the ear, hoop and flower head characters into ashes.

After cooling, sweep out the ash and slag, place the bottom of the wooden mold, and then install the tail beads. Then put on the mud, after drying, take out the bottom of the wooden cannon mold, and then burn the tail beads with charcoal fire, after completely cooling, wait for the kiln casting.

At the same time, the rest of the craftsmen made the mold core out of iron, which was equal in length to the inner diameter of the gun, and half the size of the inner diameter of the gun.

After the gun mold and gun core are cast, it is necessary to talk about the gun mold and gun core installed together. The light gun mold weighs thousands of catties, the heavy one weighs tens of thousands of catties, and the cannon core is also very heavy. With the help of simple machinery, the gun mold should be placed first, and then the mold core should be installed in the gun mold, the lower mouth should be plugged tightly, and the surrounding area should be padded with dry soil.

After the installation of the gun mold and the gun core, the bronze should be melted, and then cast into a thin sheet of three or five catties, waiting to be poured into the furnace for casting.

The refined copper is put into a pre-brick-built stove-shaped copper pouring furnace, and then the copper is catalyzed into juice with a high fire, and then the copper is gradually added.

When all the copper juice is cleared, like oil and water, and there is a golden flower and green flame on it, the copper juice will be drawn out, and gradually put into the mold, and when the wooden mold is filled, even if the casting is completed.

Within 3 days of casting, shake the mold center loose; On the 5th day, take out the mold core; On the 8th day, the soil was dug up, the cannon was put down, the two ends were raised more than 2 feet high, the mud on the mold was removed, and the cannon body was cast.

Since the newly built muzzle is uneven, it must be flushed to make the muzzle neat and smooth. The knife was slashed into the muzzle of the gun, and the inside of the gun was extremely smooth.

The muzzle and chamber must be polished and smooth, and only a smooth and rounded cannon is a good cannon.

After the bore and muzzle are processed, the fire door is drilled. The proper placement of the cannon is related to the use of artillery. Therefore, according to the size of the inner chamber, close to the bottom of the gun, use a pure steel rough drill, dipped in oil to drill the fire door, the fire door must be parallel to the bottom of the gun, it is appropriate.

"Brother, Brother Da Niu has been sleepless for more than ten days." Outside the craftsman's room, the sixth son said to Li Chen.

During these ten days, the rest of the craftsmen took turns to rest, although they were tired. But the big cow has not come out for a day since he entered the craftsman's house. The meals are brought in by other craftsmen, and it is said that when you are tired, you will find a place to lie down for a while.

"Don't die suddenly, this kid Da Niu." Li Chen said with some worry, Da Niu, the merchant is as his name suggests, and he is really a little digging. Li Chen had asked him to rest several times, but Da Niu just didn't want to, and it was useless for anyone to persuade him.

"Boom." Just as the two were chatting outside, suddenly there was a roar in the room.

"Bang."

"Whoosh, whoosh, whoosh."

I saw a colored projectile flying out of the window, and the room shook three times. Fortunately, Lijiazhuang has now lived in a brick house, and if the wooden house is a wooden house, I am afraid that the house will collapse if this cannon goes down.

"Boss, look, lives up to expectations." Da Niu patted the bronze cast cannon body and said proudly.

"You kid, you're a genius." Li Chen looked at the two cannons on the ground, one large and one small, and said happily.

This small cannon is a tiger squat cannon made according to the drawings provided by Li Chen, and this cannon actually looks like a red-clothed cannon in the Ming Dynasty.

Li Daniu, this kid, is really a genius. Li Chen only gave him the drawings of the tiger squat cannon, flowering bullets and solid bullets, and he actually drew inferences from one another and built this cannon with stronger firepower and longer range without drawings.

"Boss, look, this is a cannon, this is a small cannon, and the flowering bullet you said, the solid shell." Da Niu said triumphantly.

"Cattle Pie." Li Chen looked at this rough man and was stunned for a long time. Sure enough, I was born to be useful, and everyone has their own areas of expertise.

Behind the two, Liuzi's expression was a little depressed, as if he was the original trio of Li Jiazhuang, and he was the only one who was an idler.