Except for mortars, shells are stuffed from behind the breech, and after being stuffed in, the back has to be blocked, and this device in the city is the bolt.

It blocked the shells in front, so it naturally had to bear the pressure of the propellant gas when the gun fired, and this device had to be sealed, not only could not be pushed away by the gas pressure, but at the same time, it had to ensure that there was no leakage of the fired gas.

Actually, it doesn't matter if there is a slight leakage of gas, but the terrible thing is that the leaked air must be brought with flames, so it will be a big trouble. Once it leaks, it's almost the end of the explosion.

The role of the gun bolt is huge, in the case of meeting the pressure and not leaking, it must also ensure safety and reliability, the bolt is not in place, the gun can not be fired, and the bolt cannot be suddenly opened during the shooting. At the same time, it is important to ensure that loading, unloading and firing are quick and easy.

After decades of artillery development, two types of bolts gradually evolved, one is the screw bolt and the other is the wedge bolt. Screw bolts are generally used for breech-loading guns, while wedge bolts are generally used for rapid-fire guns.

Among these two kinds of gun latches, the screw bolt is the most used, it is like a door, open the bolt, turn the door shaft, pull the bolt to the side, and then load, close the door, turn the bolt, because there are threads inside the bolt, so after turning, it is tightened.

At the time of firing, the thread is completely dispersed due to the longitudinal stress generated by the gun gas, so it can be made lighter, but because of this thread structure, it is very complicated to build.

The wedge bolt is even simpler, it is a baffle that, when the mechanism is opened, can automatically fall down, reload, and then pull it back.

Because it moves up and down, (and there are also lateral movements.) So, when the door is closed, there are fewer opportunities to squeeze your hands in. The structure of this gun bolt is simple, and the operation is convenient and easy, but because it is the movement of the slider, it is not easy to play the role of sealing. It also has to withstand enough gas thrust when firing, so this kind of bolt will generally be heavier.

In short, one is convenient to open the door, and the other is complicated to open the door, then, if you want to increase the rate of fire, you have to start from the action of closing and opening the gun chamber, this gun latch, with a wedge gun bolt can increase the rate of fire, theoretically so.

However, there is no design for using a wedge bolt on a 155-mm gun, and if it is to be changed, it is necessary to ensure safety, then I don't know how many experiments it will take to determine, which will greatly delay the delivery time of the gun.

………

"Wow, pyramids!" The car was driving on the desert, and when they saw the huge triangular building outside the car, the people inside the car immediately let out a cheer.

After the end of the **** uncle's investigation, the time was close to the time when the pyramid country held the international defense exhibition, so from here, Qin Zhenhua took a car to the pyramid country, and on the way, he encountered this scene.

Looking at those huge buildings, at this time, Qin Zhenhua also felt some emotion in his heart: "This is the same as the Great Wall in our country, and it is also the greatest building." It is a treasure of human civilization. ”

Qin Zhenhua's words attracted the favor of the fellow receptionist Shi Ruifu, who nodded and said: "Yes, we both once had a brilliant civilization, our two countries have too much in common, and we also have a great friendship, I hope our friendship can continue to develop." ”

"That's nature, and I came with our friendship." Qin Zhenhua said: "In particular, in the field of military industry, we have also had the experience of successful cooperation. ”

Speaking of this, the two sides smiled at each other and did not mention anything to each other.

A few years ago, the political position of the pyramid countries was tilted towards the Soviet Union, and the army was also a flood of Soviet weapons, but later, for some reason, they began to lean towards the West, so that most of their domestic Soviet-made weapons had no source of spare parts.

So, they decided to eliminate some of them.

In this case, the eastern powers took action, and the MiG-21MF and MiG-23 were secretly transported from the pyramid countries to the eastern powers in this case, which played a great role in promoting the development of the military industry of the eastern powers.

The secret work at that time also fully reflected the friendship between the two sides, and now, Qin Zhenhua came with friendship.

This is a mysterious land, and can your own weapons and equipment be sold here?

However, when I came here, I didn't just come to sell arms, but there were some things I hoped would be able to make the trip.

Thinking of these things, Qin Zhenhua had a lot of thoughts.

Ahead, the flow of people gradually increased, the outline of a city gradually approached, compared with the city without water, it looked a little backward and shabby, and those caravans walking on the streets with camels constituted a special scenery.

The car ended up in front of a government department.

"This is our International Defense Show Preparatory Office, and Mr. Aria is waiting for you inside." Shreif said to Qin Zhenhua.

Qin Zhenhua nodded, and then walked in.

"Mr. Qin is here, welcome, welcome." As soon as he walked in, Mr. Arria greeted him with a smile on his face.

"Well, I'm just an assistant." Qin Zhenhua said that he has nothing to do with the boss, but when this sentence is said, the other party will never take it seriously, who doesn't know, Qin Zhenhua is famous in the world and has done a lot of business.

Recently, in the waterless country, their howitzers have already made a name for themselves.

Naturally, as a representative of the Northern Company, I came here to talk about the International Defense Exhibition.

"We learned that most of the booths you set up are indoor, so the products we exhibit will be model-based." After Qin Zhenhua sat down, he communicated with the other party.

Different countries have different national conditions, it is too hot here, and it is quite inconvenient for people to exhibit in the open air outside, so the other party decided to make it an indoor exhibition.

Since it's indoors, it's limited space after all, so if you get all the weapons directly, it will take up too much space.

The model is the main thing, and the part is the real thing, so that it is mixed and matched.

Aria nodded: "Of course there is no problem, then, what do you plan to exhibit?" We would also like to determine the size of the booth according to your exhibits. We are friends, and of course we have to meet the needs of our friends first. ”