When Chen Zhan removed the various fasteners that fixed the iron mold, Qin Chuan squatted beside him, staring intently.

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

This is the Great Steward Brand Tiger Squat Cannon that has been improved by Qin Chuan.

The barrel is three feet long, with a thick head and tail, and the muzzle is two inches and five minutes, and the wall of the barrel at the barrel position is two inches thick, and the thickness is only one inch near the thinnest part of the muzzle, and after scraping through the barrel, the thickness may only be nine minutes.

That is to say, the shape of this tiger squat cannon, like the Hongyi cannon, is made into the shape of a thick tail according to the degree of force after the gunpowder explosion, which is a more reasonable approach.

Chen Zhan took the rod and weighed it, weighing forty-two pounds.

After scraping the gun chamber and adding two wrought iron hoops to the chamber, the weight should be about forty-five catties.

The tiger squat cannon of the Ming army was two feet long and weighed thirty-six pounds, and the big one was three feet and weighed fifty pounds.

Although the wall of the barrel part of the chamber is thicker than that of the Ming army, the front tube is thin, so the weight is lighter than that of the Ming army.

In contrast, an iron cannon with a thick wall of the chamber tube will be able to withstand more gunpowder, and the range and power will be greater.

Qin Chuan was most concerned about the quality problem, so he brought his eyes to him, and carefully checked them over and over again, inside and out.

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

Except for rough spots, there are no bubbles or twists in the bore.

If by the standards of the Ordnance Bureau, this is a qualified, even high-quality iron cannon.

But for Qin Chuan, this is not enough.

He made an iron chisel and chiseled it on the muzzle of the gun a few times, and only stopped when he saw the color of the metal.

Then, Qin Chuan was stunned......

The color of this metal cross-section...... Look at whether it is white or not, gray and not gray.

And he knew that the broken wound was white, and it was called white iron.

With current metallurgical technology, 99 percent of the pig iron smelted is white iron.

This iron is very hard and wear-resistant, but it is brittle, and if it is not thick enough, there is a high risk of blowing up the chamber.

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

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

Could it be a hemp iron?

Qin Chuan touched his head, half didn't understand.

Chen Zhan on the side and Li Xuejing, who rushed to study, knocked on the barrel of the cannon, touching and listening.

After a long time, Chen Zhan said with joy on his face: "Chief steward, the quality of this cannon barrel is already quite good, even better than the quality of the artillery made by Lord Sun in Denglai." ”

Li Xuejing also nodded: "That's right, this cannon is tough on the outside and the inside, as long as it is properly maintained, the possibility of exploding the chamber is very small." ”

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

It seems that it should be a hemp iron.

A necessary condition for refining gray iron is that the silicon content must be high enough to allow the carbon to precipitate in the form of graphite, so as to obtain gray iron.

The cooling rate of this iron cannon has been well controlled, but because the furnace temperature of ironmaking 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 molten iron is very low, only a part of the graphite is precipitated, and the other part of the carbon exists in the form of carburizing, which becomes the current hemp iron.

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

So......

"Annealed."

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 Ordnance Bureau, it does not meet our requirements, and we want a gun with a lower risk of exploding, more durable, and a faster rate of fire."

"So, let's go back to the furnace and anneal, mix the toner, iron powder and horn powder, stuff it into the gun chamber, put it back in the furnace and anneal it for three hours, and the fire doesn't have to burn too hard."

Chen Zhan and Li Xuejing looked at each other.

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

The artillery factory was busy again, and under Qin Chuan's fingers, the barrel of the tiger squat cannon was quickly filled with black powder, and then it was put in the furnace and buried with charcoal for calcination.

After noon, the tiger squat cannon was taken out, the burning charcoal fire in the barrel was dug out, the outer wall was slowly cooled in the air, and the inner wall stretched out a copper pipe into it to blow slowly, so that the inner wall cooled slightly faster than the outer wall.

Second, after the barrel of the cannon was completely cooled down, Qin Chuan studied it for a while, and then laughed.

Chen Zhan and Li Xuejing breathed a long sigh of relief, and finally satisfied the chief steward.

At the same time, the chief steward's careful study also made them admire.

Because of this, they have made the best Tiger Squat Cannon to date.

Next, the fire door is drilled, and then the barrel of the barrel of the chamber is applied, and the barrel is wrapped with finely forged wrought iron bars, and the forging is fused.

The Tiger Squat Cannon forged by the Ordnance Bureau has as few as five iron hoops, and as many as seven or even more, and this big steward brand Tiger Squat Cannon only has two hoops.

Because the quality of the iron cannon itself is very good, there is no need for so many iron hoops, so it is better to reduce weight and improve mobility.

After putting on the iron hoop, it is time to scrape the barrel.

The time required for this process is short, depending on the quality of the bore of the barrel, the bore cast by the iron mold is relatively smooth and straight, so the time is short, and Chen Zhan only took a while to scrape the bore of the gun extremely smooth.

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

This speed is very fast, the craftsmen of the Ordnance Bureau take longer than this to forge with wrought iron, and if you use traditional clay molds to cast, it will take more than a dozen just to wait for the clay molds to dry.

The iron mold can be used repeatedly, although frequent heating will reduce the life of the iron mold, but it is still no problem to make ten iron cannons from a set of iron molds.

The casting time of other iron cannons will not be much longer, and after the six-pounder cannon is figured out, a cannon can be built in ten and a half months.

Thinking that a batch of artillery would be able to explode in the near future, Qin Chuan was excited.

When the spring snow melts, take the three cliffs first.

Pull dozens of cannons up, bombard the cottage wildly, and see what Wang Gang and Leopard Wu can do to block the two hanging hairs, and in the steep cottage, they will also blow him up.

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

If that guy refuses to surrender, he's dead.

Followed by the Hu family in the east village of Lan County.

Guding's Wang An, when he went out to kill Jiannu, gathered the Feng family of Chijianling and several big households to attack Lou Fu.

It's just looking for death.

When the time comes, pull the six-pounder cannon and blow his Hujiazhuang into scum.

Then they robbed him of the silver and grain of the Hu family, occupied his village, and seized his arable land.

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

……

It snowed heavily for two nights, and the snow on the ground was one and a half feet thick, and it was really a three-layer snow cover.

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

The whole Luliang Mountain is covered in silver, and the silver light shimmers in the sun after the snow, like a fairyland.

Fifth, a team headed by the chief steward of Qin marched to the western shooting range, accompanied by a three-foot-long, forty-five-pound tiger squat cannon.

The snow at the shooting range had already been partially cleared, and dozens of targets had been erected, located at a distance of thirty, fifty, sixty, and one hundred paces.

When he arrived at the shooting range, Chen Zhan took a few craftsmen to aim the tiger squat cannon at a target a hundred steps away, nailed the front and rear claws to the ground, poured ten taels of black gunpowder into the barrel of the cannon, put a large lead wrapped in linen soaked in tung oil, weighed two catties, inserted a fuse into the fire door, and used gunpowder to lead a fire path out.

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

After Chen Zhan led the gunpowder to the edge of the earthen pit, he handed the fire sickle to Qin Chuan.

"For the first shot, it's better for the chief steward to come."

"Okay."

Qin Chuan took the fire sickle and knocked it without thinking.

As soon as the sparks flashed, the gunpowder snorted and burned along the fire path towards the big steward brand tiger squat cannon.

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

Well...... Listening to this sound, it seems that there is no explosion.

Qin Chuan got up from the dirt pit and ran in to take a look, but sure enough, he didn't explode.

Chen Zhan and Li Xuejing also ran over and carefully inspected the barrel to see if there were any cracks.

There was an Emperor Guan army running towards the rear of the target a hundred paces away.

Because, most of the people who were hiding in the distance saw that the lead had crossed the wooden rake and landed on the dirt slope twenty or thirty paces behind, and it bounced a few times.

"The big steward, the cannon chamber is not cracked."

"Well, as expected, the artillery I built is so easy to crack."

"Hahaha, that's true."

"The big steward, the shot just now missed the target, and the lead hit far away."

A hundred steps away, a Guan Emperor soldier waved his hands and shouted.

"Hmm...... Go over and take a look. ”

Qin Chuan waved his hand and took Chen Zhan, Li Xuejing and others to check the lead.

Not long after, the target was moved one hundred and thirty paces away, and this time twelve taels of black powder were released, and the lead still weighed two catties.

Because the tube wall of the tiger squat cannon is thin, the two-foot cannon was only eight taels of gunpowder when the Ming army used it, and the three-foot cannon was only ten taels, compared with the weight and caliber of the shell, the amount of medicine was seriously insufficient.

There was another boom, and the lead still crossed the target and landed on the hillside behind.

"Chief steward, the firing range of this cannon is about twenty steps farther than those three-foot tiger squat cannons in the Ordnance Bureau, one is because the gunpowder is more powerful, and the other is a slightly increased dosage."

"Well, try shotshots again."

The lethality of the Ming army's tiger squat cannon can reach 30 steps with a two-foot barrel and 50 steps with a three-foot barrel.

Qin Chuan wanted to know how far his big steward tiger squat cannon could go.

For the Tiger Squatting Cannon, the data of the scattered bullets is the most important, because the main function of this thing is to release scattered bullets to kill the Shangren.

This time, 12 taels of black powder were still placed in the barrel of the cannon, and the shells were 120 shotshots weighing five coins, and then two catties of large lead were wrapped in oil-soaked linen cloth and pressed against the front of the shots.

When he was ready and made a loud noise, Qin Chuan led a group of his subordinates to run out to see the target.

The target of 30 steps was basically spent, the target of 50 steps was mostly pierced, and most of the targets of 60 steps were inlaid with lead, and a very small part was penetrated by lead.

And the big lead fell on a distance of more than eighty paces.

It seems that when this tiger squat cannon is medicated twelve taels, the effective range of large lead bullets can reach 130 steps, and the discharge bullets can reach 50 steps.

Qin Chuan was very satisfied with this range.

Jiannu's bow and arrows also had to go fifty paces before releasing the arrows, which was enough distance for the tiger to squat and shoot them.

The Tartars' cavalry generally had to advance to thirty paces before firing, and this distance was ...... To come in is to find death.

This Tiger Squat Cannon can be manufactured in batches and installed in the army.

……

Qin Chuan, who was satisfied, explained to Chen Zhan, tried it several times, and studied the best dosage for this cannon.

Then, according to the dosage of medicine, the range under different angles is measured, so as to make a range scale, standardize the medication and shooting angle, and pursue accuracy.

After the explanation, Qin Chuan rode a high-headed horse and returned to the village leisurely.

Upstairs, a fast horse suddenly arrived, bringing a very bad news: in the direction of Lanxian in the north of Jingyou, a large number of troops suddenly appeared, estimated to be two or three thousand people, and now it is less than twenty miles away from Jingyou.

It was observed that this army was supposed to be the Ming army.