For this kind of thing, it is not a high-tech thing in the late Ming Dynasty, and many craftsmen in the Ming Dynasty have learned how to build bird guns, and the actual power is not too small.

A high-quality bird gun, in fact, is not bad in terms of range, accuracy and power, and in the hands of a good shooter, it can also exert quite good power.

However, in the past, the officials of the Ming Dynasty were greedy, and the eunuchs and officials in charge of building weapons always withheld iron materials and filled their own pockets, so that the craftsmen had to cut corners to shoddy and create some unqualified bird guns to be delivered to the Ming army.

In this way, many of the bird guns used in the Ming army were of poor quality, and there were often accidents of explosions, and it also led to the fact that the bird guns never officially became the main battle equipment of the Ming army, and left a notoriety, and few people were willing to use bird guns as weapons.

However, after these craftsmen were captured by Jiannu, they were selected and all concentrated in the workshops outside Shengjing City, which was rich in coal and iron in the Shenyang area, and many workshops were built here, and a large number of blacksmiths were concentrated to create various weapons and armor for the Jiannu army, forming a large scale of production.

Jiannu perennial war, the demand for armor is also very large, and the management is strict, the quality of the armor, far more than the quality of the armor used by the Ming Dynasty official army, they have developed a very strict management system, supervise the craftsmen to create a variety of armor, once a craftsman cut corners, to create unqualified armor, will incur severe punishment.

Therefore, when Huang Taiji ordered to build as many bird guns as possible at any cost, they did not have the situation of cutting corners and filling up the number as they did before the Ming Dynasty.

Therefore, after Jiannu successfully trial-produced the bird gun, the quality of the bird gun they produced was far greater than the quality of the bird gun used by the Ming army before, and the range and power were also improved, and there was a certain lethality at the farthest seventy paces away, but it was limited to this, after all, they would not get the rifling of the Migne rifle, and they did not understand the principle of the Migne bullet, so it was a move against the sky to be able to do this step.

Huang Taiji paid attention to the situation in the Ming Dynasty in the Guan, and found out that Yu Xiaotian had no plan to use troops against them in Liaodong for the time being, but only retained the Guanning Army to temporarily stay in the Guanjin area to monitor them, and was concentrating on cleaning the officialdom in the Ming Dynasty, replacing officials, and controlling the situation in various parts of the Ming Dynasty.

Huang Taiji knew that this was the last chance left for him, so he devoted all his national strength to make craftsmen build all kinds of artillery and guns day and night, trying to use these new firearms to compete with them when Yu Xiaotian used troops against Liaodong Houjin in the future.

What the Manchu Qing Dynasty founded the country with cavalry and shooting, by this time it had already been thrown out of the clouds by Huang Taiji, and the lessons of Tongguò in front of the family firearms made them realize the power of firearms on the battlefield, and also knew that after leaving firearms, no matter how brave the samurai was, they would only be slaughtered.

They let go of the previous dependence and pride on riding and archery, and tightened their belts desperately and began to prepare desperately.

However, the days of Houjin outside the customs are becoming more and more difficult day by day, because after Yu Xiaotian came to power, Yu Xiaotian implemented extremely strict control over the export of materials from inside and outside the customs, and arrested and killed a large number of profiteers who had previously colluded with Jiannu, smuggled grain and other materials out of the customs and sold them to Jiannu, as well as officials who colluded with profiteers, so that many profiteer families suffered a catastrophe.

In addition, the navy also completely blocked the coastal areas around Liaodong, and also blocked the sea routes, basically blocking all channels for Jiannu to obtain grain from the Guannai.

Under the heavy pressure, it completely suppressed the momentum of the profiteers in the customs to risk sending materials outside the customs, which was equivalent to choking Jiannu's neck.

Due to the climate influence of the Xiaoice River period in Liaodong, the area outside the Guanxi was extremely cold, and the frost-free period was extremely short throughout the year, which also severely affected the production of grain outside the Guanxi and the development of agricultural economy.

This is also the reason why the Jiannu have always insisted on risking their entry into the customs for so many years, and they can obtain grain or assets through guò plunder, and then use these assets to buy daily necessities such as grain and cloth from the profiteers in the customs, and even they have made corresponding very strict regulations on the varieties of imported goods, and they do not want to enjoy luxury goods, but only buy their daily necessities.

Now that Yu Xiaotian has implemented strict control and control, it has cut off the way for them to continue to obtain grain and other necessities from the Guan, and their own grain production is insufficient, which has also led to the rapid shortage of food outside the Guanxi in the past two or three years.

Although Huang Taiji tried his best to order all the ministries to do their best to open up the wasteland and grow grain, the frost-free period was too short to limit their grain output, and they were never able to fundamentally solve the grain problem.

This is also the reason why Nurhachi massacred the Han people outside the Guan, it is precisely because of the lack of food outside the Guan, in order to survive, the wild boar skin came up with such a lack of morality, through the slaughter of the Han people outside the Guanxi to reduce the food and save food, even the first big traitors who took refuge in Jiannu were also slaughtered, which shows the tension of food outside the Guan.

For three consecutive years, there was a strict food shortage outside the pass, and even a large number of slaves starved to death.

In addition, Yu Xiaotian also used a ruthless trick, that is, he tried his best to provoke the relationship between the Mongolian tribes and the Jiannu, and after the defeat of the Jiannu army by the Yu family army in Guannei, the Mongolian tribes also suffered the loss of Yan zhòng.

In addition, the Mongolian tribes also realized that Jiannu was afraid of trouble, and if they continued to follow Jiannu, they might end up in a very miserable end, so after the second half of the twelfth year of Chongzhen, the Mongolian Eight Banners no longer listened to Jiannu's call.

And Huang Taiji also sensed the restlessness of the Mongolian Eight Banners, and decided to strike first, sending troops to regularly attack and slaughter the Mongolian tribes, using this method to eliminate the threat of the Mongolian tribes to them.

This also caused the Mongol tribes to eventually turn against Jiannu completely, re-regard Jiannu as a revenge, and began to constantly conflict and resist Jiannu for the survival of their own tribes.

Yu Xiaotian also ordered the government in the area of Xuanda to deliberately throw some bait to the Mongolian tribes.

It is well known that after the fall of the Yuan Dynasty, after the Mongol tribes were driven back to the steppe, the economy and technology were strictly regressed, especially many necessities of life, which were strictly dependent on the Guannai.

The Ming dynasties all used the guò mutual market to restrict the development of the Mongolian tribes, and the mutual market exploited the Mongolian tribes, and later because of the reason of the construction of the slave, it also issued an order to shut down the mutual market, and the Mongolian tribes eventually fell to the Jiannu, followed by the construction of the slave mix, and through the means of looting from the Ming Dynasty, to obtain various necessities of life.

Not to mention other things, there are two things that the Mongolians have always been inseparable from the supply of the Ming Dynasty, that is, tea and salt, Mongolia does not produce salt, and it is not near the sea, all the salt is supplied by the customs, there is no salt to eat, people have no strength, and even their cattle and horses need salt supplements, so their demand for salt has also caused their dependence on the customs is extremely high.

In addition, because of the food structure, the people of the Mongolian tribes are mostly meat-based, because they are nomadic people, they do not farm, and naturally there are no vegetables and grains to eat, they can only eat grazing cattle and sheep and other meat food, which produces their strict dependence on tea, and they can not live without tea.

After the Ming Dynasty shut down the mutual market, the Mongolian tribes had a strict dependence on Jiannu, and obtained tea, salt and other things through Guò Jiannu, and they did not smelt iron, and iron tools needed to be obtained from Guannei or Jiannu.

Although the Jiannu themselves did not produce salt and tea, they could always obtain these goods through the profiteers in the Guò Pass, and they themselves produced iron, and when the Mongol tribes obtained these materials, they were inevitably exploited by the Jiannu, and the Jiannu acted as a second-tier trader to obtain war horses from the Mongol tribes, making a great profit.

However, with the change of the situation, Yu Xiaotian cut off the smuggling activities of materials outside the customs, and also cut off the channels for Jiannu to obtain tea and salt.

In addition, the Jiannu side realized that the Mongol tribes would not listen to their calls and guard against them as thieves, so naturally they would not provide them with iron weapons, so the Mongol tribes would be miserable.

After a year, the tea and salt were exhausted, and the iron tools could not be replenished, and there was no way to build weapons without iron, so that after only a year, the Mongolian tribes returned to the primitive state, and the weapons could not be replenished, and even the arrow clusters of bows and arrows were not made of iron, and they could only reuse the bones of some animals to act as arrow clusters, not to mention weapons such as knives and guns, which could not be replenished at all.

The Mongol tribes still wanted to use the old method to enter the customs and plunder, but after Yu Xiaotian took control of the court situation, he continued to use the family army to replace the border army and guard the border passes in various places, and it was difficult for the Mongols to enter the customs and loot as before.

At this time, Da Ming threw out a bait, that is, to spread the news, telling those Mongolian tribes that it was okay to get tea and salt if they wanted to, but they must be allowed to get out of Jiannu's control, and they must not act as a dog's leg for Jiannu in the future.

If they give up cooperating with Jiannu and continue to help Jiannu to abuse, then they can reopen the mutual market in the Xuanda area and trade tea and salt with them, so that they can survive.

At this time, the Mongol tribes had been forced into a corner, and continued to mix with Jiannu, who did not trust them, and often attacked them and slaughtered them, they could not get any benefits, and it had become a dead end to oppose the Ming Dynasty, so they had to choose to give in.

Some Mongolian tribes began to submit to the Ming Dynasty, saying that as long as the Ming Dynasty provided them with tea and salt markets, then they would be willing to submit to the Ming Dynasty and no longer serve the Jiannu.

So Yu Xiaotian opened the net and agreed that some Mongolian tribes would use their cattle, sheep, and war horses to the pass designated by Xuanda, and conduct mutual markets with the Ming Dynasty, and exchange tea and salt for their war horses, cattle and sheep, as well as skins and other things.

Moreover, Yu Xiaotian also issued an order to release a group of Mongols who had been captured and surrendered on the battlefield in Guannei, and sent them out of Guanwai and returned to their tribes to act as spies for the Ming Dynasty and monitor the activities of various departments.

These captured Mongolian generals, in the pass to see the strength of the Yu army, was completely subdued, after being released, did not dare to have two hearts, became a loyal servant of the Ming Dynasty, began to act as an eyeliner and spy for the Ming in various departments, constantly spread the power of the family army, intimidated the tribesmen of those tribes, so that they did not dare to have the idea of continuing to confront the Ming.