Li Laoer led 700 cavalrymen and drove more than a thousand large carts back to his nest.

This time when he went to exterminate the Shanxi merchant caravan, although Lin Danhan took away 90% of the seized, Li Laoer also gained a lot. The two thousand kilograms of pig iron and one thousand kilograms of gunpowder he obtained could make Li Laoer have the idea of ​​casting a firearm by himself.

Back at the mountain village, the three hundred new recruits who stayed behind the mountain village were returning from the mountain with more than 200 horse thieves and captives to cut wood from the mountain to build a seven-shot cannon. The so-called seven-shot cannon is a heavy trencher that defends the city. It is operated by more than 200 people and can throw 90 kilograms of stones at a time for more than 200 steps.

The reason for the city-defying stone thief is that if this weapon is shot from a high place, the range will increase a lot. The Dadongyugouling Mountain Village where Li Laoer is located is a castle built on the high ground. As long as three seven-pin cannons are arranged in the city wall, a large area around can be controlled more than 200 steps away.

The power of the seven-pin cannon is that it can not only throw a whole piece of huge rocks, but also throw a whole basket of gravel. Put a basket of gravel on a trencher, pull it by more than 200 people and shoot it out, and hundreds of stones will be smashed down like flowers in a scattered flower, which will probably kill a large number of Jurchen soldiers.

Now that Li Laoer has brought back a thousand kilograms of pig iron and five hundred kilograms of gunpowder, he is no longer satisfied with creating new cold weapons, but plans to use these pig iron to cast a batch of firearms by himself.

In the castle, there are six blacksmiths who Li Laoer "invited" for many years. There is a blacksmith shop in the castle. Li Laoer also built a new blast furnace himself and a hand-made boring machine he built himself.

With these equipment, if you want to build a bird gun, there is no technical problem at all. There are only six blacksmiths in your hands, and only seven of them know how to build a bird gun. If you want to build a qualified bird gun, it takes one month to build a man and one month. At this time, there is less than a month before Huang Taiji's invasion. Even if the seven people work hard at full speed, they can only build fourteen bird guns at best, which is not enough to defend the city.

Cast cannons? Then don’t think about it. Just one thousand kilogram of pig iron can cast several cannons?

Li Laoer suddenly thought of one thing: it is better to cast a batch of three-eyed guns. This thing is much simpler than a bird gun. Bird guns need to first make cast iron into fine iron. Forty kilograms of pig iron can only obtain five to seven kilograms of fine iron. One thousand kilograms of pig iron on hand is only enough to build more than twenty bird guns. But it is different to build a three-eyed gun. Three-eyed guns do not require fine iron. Just cast pig iron, and cast directly, without losing too much iron. Therefore, only more than ten kilograms of pig iron can be cast into a qualified three-eyed gun.

The power of the three-eyed gun that Li Laoer wants to cast will be greater than the three-eyed guns currently used by the Ming army. The barrel has increased from one foot of the Ming army's three-eyed gun to two feet long, with an effective range of about fifty steps, which is much stronger than the thirty-step range of the three-eyed guns used by the Ming army.

Although the original fire door gun, such as the Three-Eyed Gun, is inconvenient to use in field battles, when defending the city, his soldiers hid behind the shooting holes of the hollow castle. Simple firearms like the Three-Eyed Gun can exert great power.

A five-foot-long wooden handle is installed at the back of the three-eyed gun, so that after the three-eyed gun is fired, it can be used as an iron hammer.

The casting method can be much faster. Seven people can cast more than 100 three-eyed guns in one month. Of course, the inner wall of the cast gun barrel may not be smooth enough. That's fine. Didn't Li Lao Er have a ready-made manual boring machine in his hand? He just used that thing to grind the inner wall.

The blast furnace in the copycat is a new blast furnace created by Li Laoer after he improved the contemporary blast furnace based on later knowledge. This blast furnace has a heat storage chamber, which can save charcoal and reach higher temperatures, reducing pig iron losses during casting, so that better quality cast iron can be obtained.

As for the method of casting the three-eyed gun, Li Laoer adopted the sand mold casting method to cast. The sand mold must first make a clay sand core. After burning the clay sand core, sand can be poured into it and made into a sand mold.

The biggest advantage of sand mold casting method is that there will be no bubbles when casting. If it is an ordinary mud mold casting method, the high temperature of the melt will evaporate the moisture in the mud mold into gas, which will produce bubbles in the casting, affecting the strength of the three-eyed gun, and in severe cases, it will cause a blow-off accident during launch. However, the mold sand has good breathability, which can allow these gases to escape smoothly, so that the casting can avoid the occurrence of defects such as pores.

Li Laoer first took six craftsmen to dig clay. The clay dug was first made into hollow clay sand cores. These sand cores were placed in the furnace and calcined, and were sintered into solid sand molded sand cores. In fact, they were ceramic tiles boxes.

Before casting the three-eyed gun, a wooden three-eyed gun was first made and inserted into a box filled with wet sand. The wooden three-eyed gun also dug out three holes, which were exactly the same size as the real three-eyed gun. After forming in the sandbox, the wooden three-eyed gun was taken out, and a sand casting mold of the three-eyed gun was left in the sandbox.

Pour the molten iron into the sand mold, and the wet sand quickly becomes dry. After cooling, open the ceramic box and separate the sand to obtain a three-eyed gun.

The cast three-eyed gun was then used to grind the inner chamber with a manual boring machine. The three-eyed gun with the grinded inner chamber was installed on the wooden pole and the work was accomplished. In this way, in less than a day, a manpower made a qualified and excellent three-eyed gun.

The sand mold casting method is the fastest casting method. Not only is the casting speed extremely fast, but the quality of the three-eyed gun produced is also above the upper layer. Moreover, Li Laoer's blast furnace has a high temperature and an extremely high iron temperature, and the quality of the three-eyed gun cast is extremely high.

"Try the musket." Li Laoer walked to Li Hong with a three-eyed gun that had just been built.

Li Hong picked up the wooden pole of the three-eyed gun, stood the pole on the ground, with the gun tip facing the sky, and took out a small bamboo tube from his waist. The small bamboo tube was fixedly packed gunpowder. When loading this way, the gunner did not need to calculate the amount of gunpowder to pour it, just pour all the gunpowder in a small bamboo tube.

The small bamboo tube aimed at a muzzle, poured gunpowder into the muzzle, Li Hong stuffed another projectile into the muzzle, picked up a strip, and compacted the projectile, thus completing the loading of a gun barrel. After that, the same action was repeated twice, and all the three gun barrels were loaded with ammunition.

"Test the target thirty steps away from the target." Li Lao Er pointed to the target standing thirty steps away and said.

Li Hongping picked up the three-eyed gun, and a lit fuse was hung on his neck. He held the three-eyed gun tightly with one hand, aimed at the target, held the fuse with his right hand, and stabbed it into a fire door of the three-eyed gun.

"Bang" A fire gust of the three-eyed gun musket spewed out, and white smoke filled the air, and a black dot passing through the target thirty steps away appeared on the target.
Chapter completed!