Seeing this, he had to smile bitterly.

"This battle is a matter of life and death for my Zhenla, if our army is not conquered for a long time in Nainong, when the Ming reinforcements arrive, our army will be defeated, and then the Ming people will retaliate and send firewood sticks, and my Zhenla people will be slaughtered."

At this time, Ruan Youjing also felt the weight of responsibility on his shoulders.

"Now that the rainy season has passed, our army has also transported gunpowder and other baggage from Quang Nam these days, all of which were purchased from the Nanyang red-haired merchant fleet, and with this Western weapon in hand, our army has no fear of Ming artillery." Ruan Youjing laughed and comforted the hidden Wu.

Just when the war in Dongpu was in full swing,

On the outskirts of Lawag, Luzon

On the shooting range of the Shenji Battalion in Huben Town, the Ming Army, several new types of artillery were being test-fired

Each town of the Ming army was equipped with a Shenji Association, and Huben Town was an important town, and its firearms troops were expanded into battalions.

At the range, five new guns were pushed up,

Its heavy cannon was mounted on a huge wooden gun carriage and hauled to the range by mules and horses.

Captain Brewster, the external instructor in charge of the gunnery test firing, had already arrived at the range.

"My lord, the Artillery Association Artillery Instructor Group of the Tiger Ben Array Divine Machine Battalion has been prepared." Lieutenant Brewster hurriedly trotted forward and saluted Liu Yu.

"This time, my Ming Court Firearms Department has trial-produced a twelve-pound cannon, and I led the Ming Court officials to observe here." Liu Yu nodded and let Brewster leave first.

Brewster, however, was sad and a little embarrassed.

"This time, the Ming army test-fired a new type of artillery at the suburban shooting range, and if there is an accident, I am afraid it will affect all of you."

Liu Yu instantly understood what Brewster meant, and couldn't help but look at the Spanish lieutenant in front of him approvingly.

This person is also loyal or out of the duty of an officer, hoping that Liu Yu and the others can stay away from the shooting range.

"Why, we can't even enter this Tiger Town Shooting Range." Xiao Wu, who came with Liu Yu, had a sinking face, and looked at the red-haired ghost in front of him very dissatisfied.

The generals of the Ming army behind Xiao Wu also glared angrily at this red-haired ghost.

"It's not that you don't let your adults enter the shooting range, today is a test firing of artillery, and we don't know if the test firing of this artillery will be successful, if there is a blow-up, I am afraid it will affect your lordship." Lieutenant Brewster explained to everyone with a serious face.

"During an artillery exercise, I personally witnessed a 1,600-pound copper cannon being shattered due to the explosion of the barrel, and dozens of copper blocks weighing several pounds smashed in all directions, killing and injuring more than 30 officers and soldiers present."

Captain Brewster's words made the scolding Ming generals close their mouths one after another.

Although he speaks Spanish, another Han Chinese co-chair is in charge of the translation.

But the Akito generals present also saw from Brewster's serious eyes that the situation was not good.

"It's okay, we are all military generals, if we don't even dare to enter the martial arts field for fear of artillery explosions, wouldn't it be laughing off our big teeth." Xiao Wu glared coldly at the general behind him.

"Since all the generals are willing to go to the shooting range, then Brewster, you go and prepare." Liu Yu nodded and said.

Seeing that the Ming generals present did not back down at all, Brewster had no choice but to let everyone in.

This cannon is a new type of artillery imitated by the Ming army on the basis of the red-coat cannon.

The Ming Army's Firearms Division casts its own red-coated cannons on the basis of high-quality iron materials smelted by using local mineral and timber resources in Luzon.

In the past, the red-coated cannons used by the Ming army were basically self-made iron-core copper artillery.

In fact, according to the process, in fact, the copper-core iron cannon is the best choice.

Because the copper core is made of copper, the toughness is high and can carry more gunpowder release, and the use of copper core makes the hard and brittle pig iron not directly bear the impact of gunpowder, which avoids the cracking of the gun body caused by excessive gunpowder loading when firing.

However, the problem is that to cast a copper-core iron cannon, it is necessary to cast the cannon core first, and then cast the cannon body outside the cannon core, and use the shrinkage of the cannon body material after cooling to tightly wrap the cannon core to make it a whole.

However, the melting point of copper is much lower than that of iron, resulting in the copper core being easily melted away by the high temperature of molten iron, so the casting artillery method used in the Ming Dynasty at that time was the iron core copper body.

And this process makes the amount of copper used extremely high, China is a copper-poor country, the use of so much copper will inevitably make the cost of casting cannons rise sharply, which is why the number of red-coated cannons manufactured in the Ming Dynasty are very small.

The reason is that the scarcity of copper has led to an increase in prices, and the high price makes it impossible for the Ming Dynasty at dusk to support it.

However, the Ming court in Luzon did not have such concerns, so the Philippines was rich in minerals, especially copper, and the Ming court set up a mining department in Luzon, taking over the original mining veins excavated by the Spaniards, and by recruiting local Tufan tribal laborers, they excavated iron, copper, silver and other mineral deposits.

Therefore, the Ming army did not lack the demand for copper and iron.

Therefore, casting bronze cannons and iron cannons, the Luzon Ming court was at least possible in terms of materials.

At this time, three of the five majestic heavy guns on the shooting range were iron-core copper guns, while the other two were relatively rare double-layer iron guns.

That is, the mixture of copper and iron is changed to a mixture of pig iron and wrought iron.

Generally, the carbon content is less than 0.2% is called wrought iron or pure iron, while the content is 0.2-1.7% is called steel, and the content is more than 1.7% is called pig iron.

Wrought iron is soft, has good plasticity, is easy to deform, and has low strength and hardness, while pig iron contains a lot of carbon, is hard and brittle, and has almost no plasticity.

Therefore, wrought iron can be used instead of copper as the core, and pig iron can be used as the body to achieve the effect of copper core iron cannon.

And this kind of artillery actually appeared in the Ming Dynasty.

However, due to the deterioration of China's ecological environment, charcoal is becoming increasingly scarce, and only coal ironmaking can be used.

The coal-iron-making process produces pig iron.

In addition, the poor quality of China's iron ore leads to the high content of impurities such as pig iron, sulfur and phosphorus smelted from coal, resulting in pig iron brittle and easy to crack.

The reason why many iron artillery pieces in the Ming Dynasty are prone to explosion is not because of technology, but because of China's iron ore and the use of coal smelting.

Moreover, the cost of pig iron is also a problem in the process of frying mature iron by the iron frying method.

Ten catties of pig iron can obtain one catty of wrought iron, and forging wrought iron into a gun core requires a large number of forging workers and forging man-hours, which increases the cost and lengthens the cycle.

This means that the consumption of pig iron for one wrought iron core is equivalent to ten pig iron cores.

With the embarrassing financial capacity of the Ming Dynasty at that time and the urgent demand for the number and speed of cannon manufacturing, the production quantity of low-cost pig iron cannons could not meet the demand.

Luzon is located in Southeast Asia, and the most important thing is high-quality wood.

Southeast Asia, with its tropical rainforests and pristine forests, brought countless pieces of wood to the Ming court, which was burned to obtain charcoal.

With charcoal smelting raw iron, the quality of pig iron smelted by the Luzon Ming Dynasty is far better than that of today's Qing Dynasty.

It's just a pity that charcoal is used to smelt iron, and its output has not been able to rise, which is why the Ming Court Firearms Division finally chose to trial produce two semi-long guns of different materials.

Under the command of the Spanish artillerymen, the artillery crews of the Ming army took positions one after another and began preparations before the test firing.

The five twelve-pounder cannons represented the highest level of craftsmanship in the Ming court of Luzon, and had to be taken seriously by all Ming court officials.

The craftsmen of the artillery workshop of the Firearms Division were also anxious outside the field.