The curved trajectory of the mortar is almost in line with all kinds of terrain environments, and the simple structure and relatively light gun body can also make it adapt to most combat needs, and it is also an easy-to-carry and powerful firepower delivery weapon; The barrel has ready-made, and when it is not a recoilless gun, the half-shaft sleeve actually seems to be more suitable for mortar work in terms of length and inner caliber; The gun carriage can be tinkered with by the ironworks and machine shops, and the ballistic table can be thoroughly explored by multiple test firings to make a relatively simple mechanical sight.

As for the shells...... Because the mortar is different from the previous three cannon direct-fire iron cannons, that kind of weapon is a weapon with a small curvature that is almost direct, even if the accuracy is poor, but as long as you dare to challenge its priority pass, you will be unlucky, hit the boat with the volume of the boat that the small river can accommodate, that is, one cannon sinks, and even when fighting on the flat ground, even after landing, there is enough kinetic energy to continue to sweep out a flesh and bone alley. Mortars are large curved ballistic weapons, and mortar shells that fall from the sky at a large angle cannot do this point of direct cannon fire, and every shot of a character can hit a person, a house, and a boat...... Dear, let's wash and sleep...... Therefore, Deng Shifeng had to bite the bullet and had to use a high-quality, stable explosive mortar shell.

First of all, it is necessary to solve the problem of the metal body of the cannonball, which has experience in large-scale and special-shaped steel casting, and the iron factory said that it will not take much effort to make two semi-circular and semi-elliptical cast iron lumps, although the direct casting with its own thread means that it is not at this level, but the shell body itself is cheap gray cast iron, and although the shell is made with this thing, although there are few fragments when it explodes, the hardness is also average, so it is no problem for those student workers in the machinery factory to tap a few threads. Put on the tail and outsource the stable tail and basic propellant tube assembled by the villagers in large quantities, and then install the fuse at the top and the propellant bag at the bottom during the battle, and a rudimentary mortar shell can be ready to fire.

Of course, the accuracy of such a quick and simple production is not too high, and the firing range is also deflated due to the poor processing accuracy of the shell and the lack of a closed air sealing ring, which leads to a decline, but in this way, the 3.5 kg shell can be projectile to a distance of 1.3 kilometers with the maximum charge, and Deng Shifeng has already said that it can basically meet the actual combat needs. If you really need a longer range...... Deng Shifeng said that such a small number of shells were refined with equipment in the machinery factory and could be fired farther......

After getting the body and the tail fin, the most difficult part was the production of the fuse.

Because the ballistic curve of the mortar is different from that of a direct-fire gun, and because the structure of the mortar shell has the characteristic that the warhead is always in front, Deng Shifeng naturally thought of the simplest collision needle fuse when developing the fuse of the mortar shell. This kind of fuze production is not complicated, under the protective cap of the head of the fuse, is a needle wrapper slightly larger than the blocking ring, when the shell is launched to the ground, the protective cap of the fuse is violently deformed under the impact, and finally the needle piercing wrap is stamped and hit through the blocking ring after passing through the last safety protection gap, and the lightning mercury at the bottom of the fuse is fired to detonate the shell charge. The production of this kind of fuse is very simple, but the safety surname is certainly not as good as the spring fuse, but the mountain village has not yet developed a wire drawing machine, and there are still great restrictions on the production of small and micro springs, and Deng Shifeng can only choose this kind of fuse to replace it temporarily. Moreover, through the production and research of fire caps, the production and application of thundermercury in mountain villages have been relatively mature, and the production and production are basically not too big a problem.

But even such a simple fuze has certain difficulties for the mountain village, and its biggest difficulty is not the processing and production, this kind of fuze is very high in material and processing accuracy, and the unqualified processing accuracy is easy to cause the fuse to be too sensitive, and the shell will detonate in advance before it is discharged, or the blocking ring and the needle punch wrap are too tight so that the firing pin cannot pass through the blocking ring and thus cannot detonate the internal charge; However, when it comes to machining, Yamamura, which already has a relatively stable machining capacity, is not worried about this. But if you want to make the ring and the package have the best combination of safety and sensitivity, in addition to having a very high processing accuracy, if you want the protective cap and the ring and the package to have both hardness and will not easily self-detonate and can accurately hit and fire after launching, the best material for the production of these key parts is copper!

When it comes to copper, I believe everyone already knows where the difficulty is, China has a lot of mineral deposits, and there are many reserves in the forefront of the world, but there are not many copper mines, plus ancient copper coins as a transaction currency, which makes copper more valuable. As early as the first transaction between Deng Shifeng and Huang Zhangshi, Deng Shifeng hoped to get more copper from Huang Zhangshi to help his industrial development; It's a pity that the copper material, although not included in the direct control of the salt and iron monopoly, but because of its output and actual use characteristics, it is not easy to obtain, after several transactions, Deng Shifeng can obtain not much copper, so that the consumption of copper by this consumable fuse has become the biggest problem in the application.

However, under the threat of survival, Deng Shifeng and Qin Er still decided to grit their teeth and use a small number of copper resources on it, not only for modified mortars and trial mortar shell samples were quickly taken out, but after the test, Deng Shifeng was more satisfied with the results, and Deng Shifeng set the final data and drawings.

Therefore, Luo Dan is very aware of the process formulated by Deng Shifeng, usually after a product has passed the trial and test, a new drawing will be redrawn for production use, and the original drawing will be stored for future call. Seeing Deng Shifeng's finalized drawings, Luo Dan understood that there was a new weapon, and this finalized production was one thing, but there were test samples in front of it! Samples that can pass the acceptance can also be pulled out directly, and they can be used......

It's just that this product is not a pure stereotyped mass production product, after all, the seamless steel pipe can not meet the requirements in a short period of time at the level of a small mountain village, but this does not dispel the enthusiasm in Luo Dan's heart, it is now summer and there is still more than an hour before it gets dark, after getting Deng Shifeng's consent, Luo Dan called the four comrades-in-arms who returned to the collective shack dormitory to test the gun, the soldier has a natural pursuit and preference for weapons, and after hearing that there are new weapons, several young people do not care about resting, Pulling the two students and Deng Shifeng to the warehouse of the machinery factory, they carried two modified mortars to the shooting range.

Among these two students, Qin Tian's figure is naturally because he has a good mathematical study, after all, artillery is a technical branch, not only to be proficient in work but also to have a certain level of mathematics to calculate ballistics and the like, and the other person, because he has a little mathematical foundation, plus a strong interest in this artillery bombing thing and fell in love with this kind of thing at a glance - Huang Shicheng!

Although Huang Shicheng has not been in the mountain village for a long time, it has only been a month since he was full, so it is said that he should enter the school to study with other students; However, because of his solid family background, he has been to school since he was a child, and his cultural skills should be ranked even above Qin Tian and Wang Ya in the mountain village! And because of his father's business genes, in addition to those who have received traditional education, he has also learned a lot of arithmetic, and he has a certain mathematical foundation that also makes up a lot of things in this area after following his godfather Deng Shifeng to quickly eat Xiaozao, and now he can even help Deng Shifeng teach mathematics courses to those young schoolchildren in the school!

Deng Shifeng originally planned to let him follow him for a while before cultivating his development direction, but he didn't expect that Huang Shicheng fell in love with this kind of explosive killer after seeing the three direct-fire cannon cannons, and with the deepening of his understanding of artillery, Huang Shicheng's attitude towards artillery has made Deng Shifeng determine his first artillery instructor candidate......

"The base should be shot solidly, yes, shoot down hard! If you are not afraid of force, you are afraid of not using force, and the gap between the base and the ground soil will affect the shooting accuracy...... I also want to thank you for these cast iron bumps, not only does a bad base not transmit recoil well, but it is more likely to endanger the safety of the gunners......"

"Don't fill all the fuses of the shells you take out of the ammunition box at once, the fuses installed on them will puncture the paper inside the shells and cause the gunpowder inside to pour out, unless you are sure that you can use up all the shells you have in one battle...... This is the safety regulation...... Artillery is different from infantry, and an accident caused by an infantryman's mistake may only kill himself, but an artillery mistake will not only kill himself but also kill his comrades......"

"The mortar must be cleared after each fire in the same way as the front mount, so as to avoid accidental ignition caused by the ashes remaining in the chamber during the loading process...... Don't worry about efficiency, just poke the wet brush into the barrel twice, the mortar's standing position and the structural features of the bottom firing pin allow the unburned ash to fall into a safer place below; However, at the end of each battle, the residue accumulated at the bottom of the chamber must be cleaned up......"

Although Huang Shicheng is much younger than Luo Dan and other future officers, he has the flavor of an instructor in commanding Luo Dan and them to use as mortars, and they do not have any disgust and frustration towards Luo Dan, but concentrate on completing one action after another under the command of Huang Shicheng. can make Luo Dan and their performance come from a sentence said by Deng Shifeng:

"It's not shameful to ask questions, it's more cost-effective to lose face than not knowing how to pretend to know how to mess around and kill yourself and lose your life......"

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