The target was made of thick wooden boards one inch thick. A five-two projectile actually smashed the thick wooden boards to pieces. This power shocked the craftsmen present.

"It's much more amazing!"

"The power has indeed increased a lot!"

The craftsmen kept saying praise.

But Li Laoer was still not satisfied, because even if he improved the 300-pound Folang machine, a projectile weighing one pound could not penetrate the shield car of the Later Jin army. You should know that the shield car of the Later Jin army was three inches thick and covered with cowhide and iron. It was difficult to penetrate without a projectile weighing more than two pounds.

At present, the only artillery that the Ming army can break the shield chariot of the Later Jin army was the Red Barbarian cannon and the General cannon. Both of these cannons were very heavy and had a very slow loading speed, which could not stop the advancement of the shield chariot of the Later Jin army.

The second brother found Sun Chengzong and handed over the three-pound field gun design drawing he had drawn: "The supervisor, the lower official, thinks that a batch of field guns weighing 300 kilograms designed by the lower official should be cast. The gun can fire two and a half kilograms of shells, specifically used to deal with Jiannu's shield chariot."

Sun Chengzong took a look at the design drawings, and he could see from the drawings that this was a front-loading cannon. So he asked: "Isn't this cannon a reduction of the red cannon and the general cannon? The loading method is similar to that of the red cannon and the general cannon. The loading speed is too slow and the power is too small. This cannon is not as high as low as possible."

According to Sun Chengzong's idea, although the red cannon and general cannon were loading slowly, the shells were powerful and had a very long range. These two advantages can make up for the shortcomings of slow loading speed. Li Laoer's three-pound cannon was not as powerful and range as the two heavy cannons, and the loading speed was no faster than the two heavy cannons, so he felt it was a waste.

Li Laoer took out a picture of a three-pound cannon shell from his sleeve: "The Supervisor, this is a new type of cannon shell designed by the Xiaguan. The cork support is combined with the cannon shell. When loading the cannon shell, there is no need to stuff it into a wooden board to hold your breath. After loading the cannon bag, you can stuff it in the cannon shell to complete the loading. In this way, the loading speed can be greatly improved."

Sun Chengzong looked at the design drawings of these shells and his eyes emitted a light: "If the shells are improved and the rate of fire is increased, the power of the cannon is even greater than that of the thousand-jin Fran machine cannon, and the weight is much lighter, and the loading time is comparable to that of the thousand-jin Fran machine! OK! OK! OK! If I had this powerful weapon in the Ming Dynasty, why not be afraid of Jiannu!"

Seeing the three words "shredded bullet" marked on the drawing of a shell, Sun Chengzong asked: "General Li, what is this shrunk bullet?"

"It's a slap, which is equivalent to a slap shot by a tiger squat cannon, but it is much more powerful than a slap shot and has a much longer range. This shrunk can explode from a hundred steps away. The slap shot can spray another fifty steps. The total range is 150 steps, which is much longer than a 50 step span of a tiger slap shot. Moreover, there are more projectiles inside, and the power is much greater."

The shrapnel bullet is not a flowering bullet, it does not pour gunpowder into the shell and explodes after it lands. Instead, it cleverly uses gunpowder gas to pour into the bullet body, causing the iron beads in the bullet body to spray out, forming a barrage.

Li Laoer naturally knew how to make two types of shells: cork fuze flowering shells and cork fuze explosion scavenging shells. However, these two shells still require hand-cranked tapping lathes to be made. The technical difficulty requirements are too high, so Li Laoer did not take out the two new shells for the time being.

But just the shrapnel shot made Sun Chengzong's eyes shine: "Can General Li create such a magical weapon?"

"I also ask the supervisor to assign a batch of pig iron to the subordinates. The subordinates will immediately supervise the construction of this cannon and cast a batch of shells. As long as they are cast, the supervisor will see it with his own eyes."

"Okay! I'll arrange craftsmen and pig iron for General Li." Sun Chengzong nodded while touching his beard. He knew that Li Laoer had just tested the iron-core copper-shelled gun, which was much more powerful than the original cast iron gun, and solved a large part of the air leakage problem. Of course, the cost has also risen a lot, after all, the price of copper is much more expensive.

Sun Chengzong felt that since Li Laoer could create an iron-core copper-shelled gun, it could improve the power of the Folang machine and solve the problem of air leakage, the 300-pound field cannon he designed is definitely a very useful firearm.

In the Tongzhou blacksmith workshop, Li Laoer was directing the craftsmen to transform the blast furnace.

In his previous life, he has read many time travel novels and countless posts about climbing science and technology trees. Li Laoer has also made some achievements in smelting steel. His own horse spear and three-foot-long fine steel armor-breaking cone were made by himself. A while ago, he cast a batch of excellent three-eyed guns in his own village.

Now it is not difficult for Li Laoer to improve the blast furnace and cast a cannon.

Under the command of Li Laoer, several bricklayers built a heat storage chamber outside the blast furnace with refractory bricks. The refractory bricks were all ready-made. There was an abandoned brick kiln outside Tongzhou City. The brick kiln was stripped down and the refractory bricks were moved into the blacksmith's workshop to build a heat storage chamber.

Then Li Laoer asked the carpenter to create a hand-crank blower according to his design and connect it to the blast furnace.

While improving the blast furnace, Li Laoer asked the blacksmith to help him and jointly create a large iron box for placing sand. This is not like casting a three-eyed gun. The mold for casting a three-eyed gun is much smaller than the mold for casting a cannon. The box for requiring a three-eyed gun sand mold is not very useful. The sand mold for casting a cannon needs to be placed in a larger box.

Under the command of Li Laoer, the blacksmith made a large iron box. Then Li Laoer sent someone to get fine sand.

After creating the iron box, Li Laoer asked the carpenter to create a three-pound wooden shape based on the size he provided. Then put the made wooden shape into the iron box, mix it with sand and clay, and then wet the sand, so that the sand has a certain viscosity. After taking the shape, the sand can still maintain its shape and prevent the iron from penetrateing into the sand, forming a bad casting surface.

Later, the blacksmith and carpenter were asked to cooperate to create a hand-crank crane.

The blast furnace has been renovated there, and the mold box and clay sand have been prepared here.

Li Laoer asked the carpenter to put the appearance into the mold box, then put the clay sand into the mold box, fill the gap between the appearance and the mold box, then unbox the shape, and then prepare the sand mold for casting cannons.

Pig iron blocks were placed in the blast furnace and the fire was lit. A craftsman was specially responsible for shaking the hand-crank blower to deliver air to the blast furnace. After about three quarters of an hour, the iron with red in the green was lured out by the craftsman and poured into the sand mold along the brick iron sink.

After a little cooled for a while, open the mold box immediately. While the just-cast cannon has not completely cooled, immediately lift it out with a hand-crank crane and drill a fire door while it is hot with a steel chisel.

This way, the cannon is basically completed, but the inner wall of the cannon cast by the sand mold is not very smooth. There are certain burrs and excess metal on the south side, and there are still remaining sand particles on the surface, which need to be cleaned by grinding.

——
Chapter completed!