When Chen Zhan removed the various fasteners for fixing the iron mold, Qin Chuan squatted beside him and stared at him attentively.

Soon, a cannon with a different shape from the current tiger squat cannon appeared in front of me.

This is a big manager's squat cannon improved by Qinchuan.

The barrel is three feet long and looks thick as the head and tail. The bore is two inches and five minutes. The wall of the medicine chamber is two inches thick. It is close to the thinnest part of the muzzle, but it is only one inch thick. After scraping the bore, the thickness may be only nine minutes left.

In other words, the shape of this tiger squat cannon is the same as that of the Red Cannon. It is made into a thick tail based on the degree of force after the gunpowder explodes. This is a relatively reasonable approach.

Chen Zhan took the pole and weighed it, weighing forty-two kilograms.

After scraping the cannon chamber and adding two iron hoops to the medicine chamber, the weight should be about 45 kilograms.

The Ming army's tiger squat cannon was two feet long, weighing thirty-six kilograms, three feet large, and fifty kilograms.

Although the pipe wall of this big manager's tiger squat cannon has a thicker pipe than that of the Ming army, its front pipe is thinner, so its weight is lighter than that of the Ming army.

In contrast, iron cannons with thick walls of the medicine chamber can withstand more gunpowder and have greater range and power.

Qin Chuan was most concerned about quality issues. He put his eyes in front of him and carefully checked them inside and out.

In the end, he and Chen Zhan unanimously confirmed that there were no cracks in the barrel.

Apart from the rough spots, there are no bubbles or distortions in the inner chamber.

If you follow the standards of the Military Weapon Bureau, this is a qualified or even high-quality iron cannon.

But for Qin Chuan, this is not enough.

He made a chisel, chiseled it in the muzzle a few times, and stopped after seeing the color of the metal.

Then, Qin Chuan was stunned...

The color of this metal section... looks white or gray.

He knew that the white fracture was called tinplate.

With current metallurgical technology, 99% of the pig iron refined is white tin.

This iron is very hard and wear-resistant, but is very brittle. If it is not thick enough, the risk of frying is very high.

The gray one is called gray iron, and Qin Chuan wants this kind of iron.

But, what's going on with this gray and white?

Is it tinsel?

Qin Chuan touched his forehead and couldn't figure it out yet.

Chen Zhan and Li Xuejing, who came to study, hit the cannon barrel, touched and listened.

After a long time, Chen Zhan said happily: "Master, the quality of this gun barrel is quite good, even better than the guns made by Lord Sun in Denglai."

Li Xuejing also nodded: "That's right, this cannon is tough on the outside and hard on the inside. As long as it is properly maintained, the possibility of a blow-off is slim."

However, Qin Chuan shook his head and sighed in annoyance.

It seems that it must be tinsel.

A necessary condition for refining grey tin is that the silicon content must be high enough to allow carbon to precipitate in graphite form, thereby obtaining grey tin.

The cooling speed of this iron cannon has been well controlled, but because the furnace temperature of the iron smelting is not high enough, it cannot reach the melting point of silica in iron ore, and the current technical conditions cannot add silicon, so the silicon content in the iron is very low, only a part of graphite is precipitated, and the other part of carbon exists in the form of carburizing, which becomes the current tin.

This iron is still very brittle, and the risk of blowing up is still very high.

so……

“Annealing.”

Qin Chuan slapped his thigh and decided to continue the heat treatment without hesitation.

"Although the quality of this gun is better than that made by the Military Intelligence Bureau, it still does not meet our requirements. What we want is a gun with a lower risk of blowing, more durable and faster firing rate."

"So, go back to the furnace and anneale, mix the toner, iron powder and horn powder, stuff it into the barrel, put it back in the furnace and anneale for three hours. The fire does not need to be burned too hard."

Chen Zhan and Li Xuejing looked at each other.

After a while, Chen Zhan finally nodded suddenly: "Okay, annealing."

The artillery factory was busy again. Under Qin Chuan's fingers, the cannon of the tiger squat cannon was quickly filled with black powder, and then put it in the stove and buried with charcoal to calcinate.

After noon, the tiger squat cannon was taken out and the charcoal fire burned in the cannon chamber was dug out. The outer wall slowly cooled in the air, and a copper tube was extended into the inner wall and slowly blown the air, so that the cooling speed of the inner wall was slightly faster than that of the outer wall.

Second, after the gun barrel completely cooled down, Qin Chuan studied it for a while and then started to smile.

Chen Zhan and Li Xuejing breathed a sigh of relief, and finally satisfied the manager.

At the same time, the serious and careful study of the big manager also made them admire him.

It is precisely because of this that they built the best tiger squat cannon to date.

Next, drill the fire door, then put the iron hoop on the gun barrel in the drug chamber, wrap the gun body with finely forged iron bars, and forge and fuse it.

The tiger squat cannons forged by the Military Weapon Bureau ranged from five iron hoops to seven or even more. This big manager's tiger squat cannon only had two hoops.

Because the quality of the iron cannon itself is very good, so it is better to reduce the weight and improve mobility than to use so many iron hoops.

After getting on the iron hoop, it was time to scrape the cannon chamber.

The length of this process depends on the quality of the barrel bore. The inner chamber cast by the iron mold is relatively smooth and straight, so the time is short. Chen Zhan only took a while to scrape the barrel bore very smooth.

Qin Chuan roughly estimates that it would take about four to five to build a tiger squat cannon, not counting the time to cast iron molds.

This speed is very fast. The craftsmen of the Military Weapons Bureau spent more time with cooked iron than this. If they were cast with traditional clay molds, it would take more than a dozen just to wait for the clay mold to dry.

Iron molds can be used repeatedly. Although frequent heating will reduce the life of the iron mold, it is still okay to build a set of iron molds with ten iron cannons.

The casting of other iron cannons will not take much time. After the six-pound cannon is found, one cannon can be built in half a month.

Qin Chuan was very excited when he thought that a batch of artillery would be blown up soon.

When the spring snow melts, first take three cliffs to start the operation.

He pulled dozens of cannons up and bombed the counterfeit village. Seeing what Wang Gang and Bao Wu had to use to block the two slings, he would also have to slam the steep counterfeit village.

After the three cliffs were settled, it was Ren Liang's turn.

If that guy refuses to surrender, he will be dead.

Next was the Hu family in Dong Village, Lan County.

The king an of Guding actually gathered the Feng family and several big families in Chijianling to attack Loufan while he was out of the frontier to kill Jiannu.

It's simply seeking death.

At that time, pull the six-pound cannon away and knock his Hujiazhuang into a slag.

Then he robbed the money and grain of his Hu family, occupied his farm, and seized his arable land.

Taking down the Hu family is equivalent to knocking on the gate of Lan County, because Dongcun is the gate of Lan County.

...

The heavy snow fell for two or two nights, and the snow on the ground was as thick as one and a half feet thick. It was really covered with three layers of snow.

The Fen River also has a thick layer of ice, covered with a thicker layer of snow.

The entire Luliang Mountain is covered in silver, and the silver light shines in the sun behind the snow, as if it is a fairyland.

The fifth place in the artillery building was that a team led by the Qin Dashi went to the western shooting range, and a three-foot-long and forty-five-pound tiger squatting cannon was accompanied by.

Some of the snow in the shooting range had been cleared out, and dozens of targets were erected, located at a distance of thirty, fifty, sixty and one hundred steps.

When he arrived at the shooting range, Chen Zhan and several craftsmen aimed the tiger squat cannon at a target a hundred steps away, nailed the front and rear paws to the ground, poured ten taels of black gunpowder into the barrel, put a large lead piece wrapped in linen soaked in tung oil, weighing two pounds, insert a fuse into the fire door, and use gunpowder to lead a fire out.

Qin Chuan, Wang Jizong and Li Xuejing hid in the pit, while others were rushing far away.

After Chen Zhan led the gunpowder to the edge of the earth pit, he handed the scythe to Qin Chuan.

"The first time, it's better for the manager to come."

"good."

Qin Chuan took the scythe and knocked without thinking.

The spark flashed, and the gunpowder slammed and burned down the fire road towards the tiger squat cannon.

Qin Chuan hurriedly lay down, and then heard a "boom".

Well... I heard this sound, it didn't seem to be blown up.

Qin Chuan got up from the pit and ran in to see that it was indeed not explosive.

Chen Zhan and Li Xuejing also came over and carefully checked the cannon barrel to see if there were any cracks.

A Guandi Army ran to the rear of the target a hundred steps away.

Because most people hiding in the distance saw the lead over the wooden rake and landing on the soil slope twenty or thirty steps behind, and bounced a few times.

"The big manager, the gun barrel has not cracked."

"Well, as expected, the cannon I made is not so easy to crack."

"Hahaha, that's the case."
To be continued...