Several key points of Zhang Zhun's request are related to the navy. The Franc machine cannon that Zhang Zhun wanted to cast was mainly used in naval battles. This point is different from the casting purpose of the Ming army. The Ming army's cannon was mainly used for land warfare, and the cannon used in the naval warfare of the Ming Navy Division, and the cannon of the infantry army, were cast in a mold. But Zhang Zhun is different. What Zhang Zhun needs is a special naval artillery, and he does not need to consider the use of land.

First of all, the range of the artillery should be long, at least two miles, and if it is more than three, it will be even better. In a naval battle, three miles away, it is necessary to fire artillery to deter the other side. If the range is less than two miles, then it is better not to.

Secondly, the rate of fire of the artillery should be fast, at least two shells per minute, and it would be better if it could fire three. The hit rate of naval artillery is too low, and whoever can shoot more shells in the same amount of time has a greater chance of hitting the target.

Again, the artillery should be light, not more than 800 catties. Because the carrying capacity of the Cangshan ship is not large, the keel is not strong enough, and the heavy artillery can easily cause the warship to lose its flexibility and maneuverability, and even lose its balance, thus capsizing.

Again, it is required that the recoil is small. The draft of the hull of the Cangshan boat is relatively shallow, and the recoil is too large, which can easily cause the hull to capsize. Even if the ship does not capsize, it will seriously affect the operation. Therefore, the recoil of the Franc machine gun, which had to be reduced somehow, required the use of specially made gun carriages.

For a long time in the future, Zhang Zhun's main naval force will be ultra-light Cangshan ships, with a displacement of only 70 tons and a deadweight of only 30 tons, which are ultra-light combat ships. A ship with such a small displacement and a cannon is originally a chicken pulling a cart, beyond its reach. However, for the sake of the needs of the battle, it had to be so.

According to Xue Zhidie's design, there were only three gun emplacements on both sides of each Cangshan ship, in other words, the entire ship had six guns. Compared with other warships of the Ming Dynasty, the Cangshan ship actually had six guns, which is already a remarkable design. However, compared with the hundreds of cannons of Western warships, six cannons are completely out of the stream! Moreover, the calibers are also too different. In general, the caliber is too small.

The caliber of the Franc machine artillery commonly used by the Ming army is the size of a small bowl, which is about 60 mm when converted. The caliber of 60 mm, and the use of black powder, is not powerful in any way. Of course, there are also Franc machines with a caliber of 120 mm, but the weight of such a Franc machine is already close to 2,000 catties.

The powerful redcoat cannon is the size of a sea bowl (ranging from 110 to 130 mm). Such a heavy artillery is too dangerous to be mounted on the Cangshan ship. For the time being, Zhang Zhun doesn't need a red-coated cannon yet. Of course, the technology of the redcoat cannon cannot be completely ignored. After all, with the development of the times, the redcoat cannon gradually became the mainstream. It's always good to start R&D early and plan ahead.

From the point of view of charge, the Franc machine is a breech gun, the cardinal cannon is a breech gun, and both types of artillery have their own advantages and disadvantages. In naval warfare, the pursuit of a long range, the redcoat cannon clearly prevailed. However, Zhang Zhun does not have a warship to set up a redcoat cannon now, so he can only focus on the Franc machine artillery.

Sun Qinkai mentioned his professional skills, but he was not wooden at all. Compared with the numbness and confusion just now, Sun Qinkai has a deep foundation in the field he is good at. Anyway, he is also a disciple of Xu Guangqi, and he has studied cannon casting technology with Xu Guangqi for eighteen years. He has theoretical knowledge, as well as practical experience, and even practical experience. He explained the key elements of the cannon casting, and finally said: "We will first cast the sample, and then test it in combination with the Cangshan ship, and improve it one by one. ”

Zhang Zhun nodded and said, "Very good!" Now let's determine the basic specifications of the artillery. ”

Zhou Shiwen and Sun Qinkai both listened attentively.

What Zhang Zhun wants to implement is standardized production.

The firearms of the Ming army are too varied and the caliber is too complex, and there are dozens of different calibers for the firearms alone. The caliber of the cannon is also quite a lot. From dozens of pounds of tiger squat cannons to tens of thousands of pounds of red-coated cannons, there is everything. There are too many calibers of cannons, which naturally brings a lot of confusion to the soldiers. Guns of different calibers have different charges. If you load less, you won't be able to hit far, and if you load too much, you will blow up. In fact, accidents in the explosion of Ming artillery often occurred.

After research, it was decided that the caliber of Brigadier General Zhang's Franc machine gun was set at 70 mm. Because of the steel used to cast the cannon, if the pig iron is better, it can withstand higher chamber pressure. The caliber is larger, the charge can be a little more, the firing range is naturally a little farther, and the power can of course be a little greater.

Of course, while studying the casting of the Franc machine cannon, you can also study the redcoat cannon by the way. After all, the real royal road is still the red-coated cannon. When all the conditions were met, Zhang Zhun wanted to build dozens of treasure ships, each with more than 100 red-coated cannons, to show off his might in the world's oceans, and practice cannon diplomacy.

With the strong support of Zhang Zhun, the research on the casting of the Franc machine artillery was fully rolled out. Zhang Zhun set up an artillery research institute, led by Sun Qinkai, with Zhou Shiwen and other craftsmen cooperating. Sun Qinkai did have relevant knowledge, and under their guidance, the craftsmen did things step by step, and soon, the first sample cannon was cast.

"Whew!"

At the artillery test site, Sun Qinkai personally lit the fuse.

"Tom!"

There was a loud bang from the Franc gun.

After the fire flickered, the shells landed in the open space two miles away.

With such a range, it can only be regarded as barely passing. Clearly, there is room for improvement. The reason for the inspection is that the airtightness is not done well. As mentioned earlier, the Franc machine gun is a breech gun, which is loaded from the breech. Due to the need to reload from the breech, the barrel could not be completely sealed. If this technical detail is not done well, the power of gunpowder will be lost a lot.

According to the results of the actual test, Sun Qinkai quickly made corresponding improvements. Soon after, a second prototype was cast. At the same time, he improved the related gunpowder. According to Zhang Zhun's suggestion, he added some copper oxide powder to the gunpowder to enhance the power of the gunpowder.

"Tom!"

The second prototype gun, the first fire.

There was a loud bang, and the shells flew out in the distance.

This time, the shells landed three and a half miles away.

Three and a half miles!

"Well, that's good!"

Zhang Zhun praised on the spot.

With such a range, it can basically meet the needs of naval warfare.

However, Sun Qinkai was not satisfied.

On the basis of the second sample gun, Sun Qinkai once again made a number of detailed improvements. Soon, a third prototype gun was made, which was also pulled to the test site.

"Tom!"

A third sample gun was fired.

There was a loud bang, and the shells flew out in the distance.

This time, the shell actually landed four and a half miles away!

Four and a half miles!

"Good!"

Zhang Zhun couldn't help but scream.

Four and a half miles, such a range is enough for the Franc machine artillery to raise its eyebrows.

The firing range of 2250 meters is nothing compared to the artillery of later generations. However, at the time, it was already a remarkable achievement. It must be known that the red-coated cannon with a larger caliber and heavier weight has a firing range of about 5,000 meters (ten miles). In a naval battle, the range of four and a half miles is enough to overwhelm ordinary enemy ships.

Of course, having a long enough range does not mean enough combat effectiveness. The use of Franc machine artillery is inseparable from the type of shells. Depending on the situation, different shells were used, which was an important feature of artillery in the late Ming Dynasty. Therefore, in addition to solid shells, the range of other shells of various colors was tested.

"Whew!"

"Tom!"

Franc machine cannon, fired again.

This time, grapeshotfire was fired.

The so-called grape bomb is actually somewhat similar to the shotgun of later generations. Use a small frame, or a few wires, or a rotten net pocket, pack a bunch of small iron balls together, stuff them into the barrel, and then fire them out, forming an overwhelming rain of bullets, causing a large area of damage to the target. Compared to flowering bullets, grapeshot bullets are much more reliable and powerful. If the enemy's team comes into range in a dense manner, the enemy will definitely fall one by one.

However, the lethality of grapeshotfire is also obvious: the range is very short. The average Francophone cannon can only shoot grape shells to a distance of 100 zhang (about 330 meters). However, the artillery cast by Sun Qinkai can successfully shoot grapeshot to a distance of 150 zhang (about 500 meters), which is a full 50% increase in range.

However, Sun Qinkai was not satisfied, continued to improve, and in the end, successfully launched the grape bomb to a distance of 180 zhang (about 600 meters). This distance is basically the distance at which the redcoat cannon fires grapeshot. Compared with the Francophone artillery, the red-coated cannon is still very rare, and unless it is a major battle, it is difficult to see the red-coated cannon.

This range means that as long as the enemy enters this range in large numbers, it can be directly fired with grapeshot. The general cavalry charge, that is, at this distance. In other words, Zhang Zhun could have directly covered the past with grapeballs when the opponent's cavalry launched a charge. As long as there are enough shells, the enemy's cavalry will fall into a large area.

For naval battles, a distance of 600 meters is also quite a suitable distance. At this distance, the solid bullet basically misses, and the power of the grape bullet is fully displayed. As long as the enemy ship enters the range of 600 meters, the three guns together bombard each other with grapeshot, and the effect is absolutely good. After being equipped with this kind of artillery, no matter how small the Cangshan ship was, the enemy ships would not dare to ignore it.

"Whew!"

"Tom!"

After experimenting with grapeshot, the Franc cannon was fired again.

This time, it was a chain bullet that was fired.

The so-called chain bullet is actually two small iron balls connected by iron chains. Of course, big iron balls are also possible. The greater the weight of the iron ball, the greater the lethality and the closer the range. The main lethal principle of chain bullets is to directly cut off the target in high-speed motion. Whether the target is a human body, a mast, a canvas or something like that, if it is hit by a chain bullet, it will be torn apart.

Later generations reported that a person riding a motorcycle was speeding by and was cut off on the spot by a power line across the road. A chain bomb is one such wire. At range, chain bullets are the most brutal weapons, more ferocious than grapeshot. If it hits a person's body, it will directly cut the person into two parts. If it hits the body of a war horse, you can also cut off the horse's head directly.

However, the disadvantages of chain bullets and grapeshot bullets are the same, both have too close range. Moreover, the chain bullet is not easy to control the target. The movement of the two iron balls in mid-air is irregular, and no one knows where it will fly. In general, both shells were used to arm the navy. If you use it on land, you have to face a dense crowd of enemies in order to be powerful.

After testing, the range of general chain shells is about the same as that of grapeshot shells, which is about 600 meters. In naval warfare, the main use of chain bullets is to tear the sails of enemy ships and break the masts of enemy ships, followed by anti-personnel personnel. In terms of efficiency, Cangshan ships can also do it. Zhang Zhun's favorite wolf pack tactic, as long as a few Cangshan ships surround you, a piece of chain bullets smashed over, and the sails of the enemy ship can be torn to pieces.

In addition to chain and grape shells, the Franc cannon often fired so-called flowering shells, which were shells that could explode. However, in terms of fuze technology at that time, the reliability of the flowering bomb was really not high. At the same time, due to the use of black gunpowder, the flowering projectile with a caliber of only 70 mm will not be lethal even if it successfully lands and blossoms. It's not as good as grapes. Therefore, in order to highlight the focus of the research, Zhang Zhun does not recommend the study of flowering bombs for the time being. It's better to honestly do a good job of solid bullets, grape bullets, and chain bullets.

After three consecutive tests, Sun Qinkai devoted himself to the improvement of the Franc machine gun with more vigorous energy. His eyes, under Ning Lingwei's treatment, also began to gradually improve. All this makes Sun Qinkai work very hard. He often forgot to sleep and eat, and stayed up all night to be busy, earning him the nickname "Artillery Maniac".

Because the casting of the artillery was mainly due to Sun Qinkai, Zhang Zhun asked Sun Qinkai to name the artillery. Sun Qinkai finally named the artillery "Flying Dragon Cannon", taking the meaning of the flying dragon in the sky. Soon, the first batch of flying dragon cannons began to be mass-produced and installed on the top of the Cangshan ship.

Zhang Zhun also often went to the artillery research institute to put forward some opinions on the construction of the surname. Although Zhang Zhun is not clear about the details of artillery manufacturing, there are many differences between the artillery of later generations and the artillery of the Ming Dynasty, but some experience of later generations is useful after all. It is rare that Sun Qinkai has relevant experience and knowledge, and he can integrate it faster than Zhou Shiwen and others. After absorbing Zhang Zhun's suggestions, Sun Qinkai's improvement, although it was bit by bit, was a real improvement.

When Zhang Zhun was immersed in the production of cannons, a series of changes took place in the surrounding area.

First of all, it was Yang Wenyue, the governor of Denglai, who officially stepped down and was transferred to the governor of Fujian.

This governor, on the ground in Shandong, is really not good. The Ming Dynasty has never had an official at the governor level, who was caught by the Tartars, and he really set a precedent. But because of the good concealment, Emperor Chongzhen didn't know about it. After receiving the recital of the annihilation of the Tatars of Tianheng Island and sending someone to inspect the head of the Tatars, Emperor Chongzhen was very satisfied. Since Emperor Chongzhen is very satisfied, it is a matter of waiting to be promoted to become rich. From the governor of Denglai to the governor of Fujian, it is a relatively large promotion.

(To be continued)