Yu Xiaotian gave the black head two months, and when he went to sea, he replenished his ship with enough supplies, and also equipped the war team with two tiger squat cannons to strengthen their firepower on land.

Just two days after sending off the black head, Yu Xiaotian got two good news one after another, one is that he sent Zhao Mazi's fleet to Foshan, Guangdong, before the festival, returned to Nanri Island, and their trip south to Guangdong was quite smooth, although they encountered two pirates on the way who tried to rob the ship, but when they saw that their fleet was a group, they all knew the difficulty and retreated.

After finding the Feng family, they purchased more than 20,000 catties of refined iron from the Feng family, and the Feng family was very satisfied with this business, and the price was relatively fair, and told them that as long as the sea wolf still wanted pig iron, they could continue to look for them Feng family, and they didn't dare to say how much they wanted, but at least there was no big problem in providing them with 500,000 catties of refined iron a year.

In this way, the problem of iron shortage on Nanri Island has been alleviated to a great extent, and there is no shortage of raw materials for casting cannons, including other iron-using projects, which have also been greatly alleviated.

In addition to pig iron, they also purchased thousands of catties of wrought iron, and at the same time greatly met their needs.

The second good news was brought to Yu Xiaotian by Blacksmith Zhang, who has been concentrating on the creation of the gun pipe since he arrived on Nanri Island.

This blacksmith Zhang can be described as an iron idiot, and he likes to study this kind of thing very much, and Yu Xiaotian also tells him some about the process of building a gun pipe from time to time.

According to the ready-made samples and the process of building the gun pipe that Yu Xiaotian told him, Zhang Blacksmith began to explore continuously, and Yu Xiaotian was also tossed by him.

At first, the quality of the gun pipe he made was not successful, but with his continuous efforts, coupled with the continuous transformation and production of some new tooling to build the gun pipe, the craft became more and more refined, and by the time of the year, he finally succeeded in creating a usable gun pipe, and loaded it with gunpowder for testing.

When Yu Xiaotian heard the news, he was so happy that he almost fainted, he had solved the problem of artillery now, and the next step was to wait for mass casting, and now someone helped him solve the problem of muskets, so he could basically achieve self-sufficiency in weapons in the future.

So he immediately ran into the ironwork to see the first usable pipe that the blacksmith had made for him.

This gun tube is more than four feet long, about one meter three, weighs three and a half pounds, the diameter of the inner chamber of the gun tube is about fifteen millimeters, which is built according to Yu Xiaotian's idea, the gun tube is hexagonal on the outside, at the end of the gun tube, there is a screw to close the tail of the gun tube, and there is a small hole on the right side of the tail of the gun tube, which is the ignition door of the gun tube.

Yu Xiaotian took the gun tube and observed it carefully, the whole gun tube was very straight, and after unscrewing the screws at the back, he observed the inner chamber of the gun tube in the light, and it can be seen that the inner chamber was drilled very smooth.

This gun pipe as a whole is already quite good, but also in accordance with the way Yu Xiaotian said, first hammer the rough iron repeatedly into fine iron, and then into iron sheets, roll the iron pieces on an iron rod, beat and forge the interface, and then make a thick iron pipe, outside the iron pipe, heat and forge it into a whole, after completion, use a drill bit to drill the smooth and straight bore drill, and then tap the wire in the back, install screws to seal the tail, open a fire door, this gun pipe is completed.

But it is easy to say, but it is difficult to do, which requires a considerable skill of the craftsman who builds the gun tube, and it takes more than ten days to make a lot of special tooling to create a qualified gun tube, if the craftsmanship is not good, the scrap rate of the gun pipe is very high, and three can make one is good.

Blacksmith Zhang also continued to explore, and gradually learned this craft, which is also related to his good foundation in ironsmithing, otherwise, it is estimated that he will have to explore for half a year, and he may not be able to create a qualified pipe.

In Blacksmith Zhang's opinion, this time he was able to create such a qualified gun, and Yu Xiaotian also contributed a lot, telling him that many things were very useful, so that he would have to avoid detours and explore by himself, and he could directly follow the path indicated by Yu Xiaotian and gradually test the test, so that he could make such a useful gun tube so quickly.

Don't look at Yu Xiaotian's skill of striking iron, even if he gives him good material and lets him fight a knife, he may not be able to beat it, but he knows a lot of things, and sometimes promotes a technique to move forward, in fact, all that is needed is an idea, after having an idea, it is not very difficult to realize the technique, of course, as long as it is not a leapfrog that greatly exceeds the level of the technique at that time, it is possible to achieve it.

And Zhang Blacksmith also learned a lot about making guns from Yu Xiaotian, and naturally took a lot of detours during the trial production, which made him successful in a relatively short period of time, and there is another point that Zhang Blacksmith has never talked about to anyone, in fact, he himself is a craftsman, his ancestors are craftsmen, and his ancestors knew how to build three-eyed guns before, and Zhang Blacksmith actually mastered some skills related to making firearms.

Later, for some reason, Blacksmith Zhang ran away incognito and settled in Donghai Village, and Blacksmith Zhang has never mentioned this matter to anyone.

With these foundations, Blacksmith Zhang has a unique natural advantage when he is groping for the construction of the bird's gun, which is why he has successfully built the gun tube in a relatively short period of time with only some theoretical knowledge and a few ready-made samples.

After Xiaotian inspected this gun, no problems were found, and Blacksmith Zhang had used this gunmetal to test shoot several times, but no problems such as explosions or cracks were found in the gun, so there was no problem with the practical safety of this gun.

However, this gun tube is only a barrel at present, and other parts have not yet been assembled to form a practical arquebus, so when the test is fired, it can only be fixed on a wooden table with a U-shaped iron nail, and aimed at a wooden rake in the distance for firing test, so as to test the safety and shooting accuracy of this gun tube.

Yu Xiaotian went to watch the landing point of the bullet hole of the wooden target, because it was fixed on the table and aimed and launched, so it avoided the impact of human beings on the accuracy, the landing point of several projectiles on the wooden target was very dense, basically concentrated in the white bullseye area of the size of the bowl, only the first two shots fell outside the bullseye because they were not aimed, and after the adjustment, the projectile landing point was much more accurate.

"How far away was the target from the mouth of the gun during the test firing?" Yu Xiaotian turned his head to blacksmith Zhang and asked.

Blacksmith Zhang hurriedly replied: "If you go back to the big boss, the small one has just started to test fire, and the target did not dare to be set too far, and it was placed thirty steps away!" ”

Yu Xiaotian observed the wooden target, this wooden target is a thick wooden board temporarily found by a blacksmith, the thickness is about an inch or so, and several shots of the test shot directly penetrated this wooden target, indicating that the shooting power of this gun tube is quite good, at least when shooting at unprotected targets, it can basically guarantee very sufficient kinetic energy thirty steps away to ensure the lethality of living targets.

So Yu Xiaotian nodded and said, "Yes, but thirty steps is a little close, then try, put the target at a distance of fifty steps and seventy steps, and then try the accuracy and power!" ”

So in the afternoon, the shooting range was busy again, and from time to time began to hear the sound of guns again, according to Yu Xiaotian's requirements, the wooden target was placed fifty and seventy steps away, and the gun tube was still fixed on a wooden platform to aim and fire.

The result of the test is that at a distance of 50 steps, the accuracy and power of this gun tube can also be guaranteed, the dispersion of the gun drop point is only expanded, but it is still within the acceptable range, the drop point is concentrated in the size of the basin, although the one-inch thick plank is not all penetrated, but most of the gun still effectively penetrates the thick plank, which means that within 50 steps, the projectile shot out by this barrel can still cause fatal damage to a living target.

However, after 70 steps, the firing and accuracy of the gun tube began to decrease a lot, and on the large target used as a target, the landing point of the gun began to fall off the target, and the power of the projectile also dropped sharply, and the projectile was also concentrated in the lower part of the target, and it was no longer able to effectively penetrate the wooden board.

Therefore, the effective firing range of such a gun tube is about 50 steps, and after more than 50 steps, the kinetic energy consumption of the gun bullet begins to be serious, so that the power and accuracy of the gun bullet can no longer be guaranteed, and the target is basically taken care of by God, and if the target is protected by armor, it cannot be guaranteed to effectively kill the target.

Such an effective range, even the bird gun is not as good, the bird gun also claims to be able to hit seventy paces away, but this kind of gun shot by the gun can't guarantee the shooting accuracy and power of seventy steps away, Yu Xiaotian was a little disappointed in this, but after thinking about it, he was relieved again, he asked Zhang Blacksmith to build this gun tube, and the bird gun of this era is different.

The most important thing is that the caliber of the gun tube was increased to 15 mm by him, which exceeded the common caliber of about 8 mm to 12 mm in this era, and the mass of the projectile was greatly increased, but for the convenience of use, the gun tube could not be made too long, which also made the ratio of the caliber and the length of the gun tube decreased a lot, and in order to ensure the safety of the gun tube, the charge was not increased much, so it is understandable that the effective range was reduced compared with the smaller caliber of the bird gun.

Although the effective range and accuracy of this gun tube are reduced compared with the bird gun, but in fact the power is much more than the bird gun, especially within the effective range, the power of this caliber increased fire gun is much more powerful than the common bird gun, don't look at the penetration may not necessarily increase much, but because the mass of the projectile has increased a lot, the kinetic energy that can be transmitted to the target has increased a lot, within fifty steps, as long as the person is hit, whether he is wearing armor or not, even if it does not penetrate the armor of their body, The energy carried can basically ensure that the living target can be knocked down with one shot, at least there is no problem in making it incapacitated.

(Bad luck!) I actually started to have a fever for the third time today! It seems that there is indeed something wrong with the body! It's just a small cold, but it hasn't gotten better for a week, and it had a fever of more than 38 degrees last night! I'm going to deliver water today, I don't know if I can update another chapter in the afternoon! If it doesn't work, I'll take a day off from work! ）