Chapter 966 Extreme Weight Loss (First two chapters)
This kind of thinking is very counterintuitive in this era. In Professor Liu's opinion, it is well known that the bounce of a gun when it is fired is random and there is no pattern.

Gao Zhendong laughed. "In fact, as long as it is designed properly, the bounce of the machine gun can be controlled to be mainly concentrated in a certain direction. You should have noticed that there are two types of tripods for heavy machine guns. One is with two legs facing forward and one leg facing backward, and the other is the opposite. The tripod with two legs facing backward can offset each other to a certain extent, suppress the left and right bounce of the gun, and concentrate the movement mainly in the vertical direction."

Professor Liu drew a few lines on his notebook and said, "Well, your idea makes sense, but can a gun mount made like this really guarantee accuracy? Judging from the indicators you mentioned at the meeting, this gun is already top-heavy and bounces a lot."

Whether it is the Russian PK/PKM or our 12.7 heavy machine gun, the gun body is heavier than the gun frame. You can imagine that this thing must have serious jumping because the center of the jumping is on the gun body. The heavy gun body can easily cause the light gun frame to jump together.

Gao Zhendong said, "Let's put aside the question of whether the vibration is very severe and continue to talk about the gun rack. On this gun rack, we removed all unnecessary parts and relied purely on the elastic deformation of the gun rack to offset the recoil exerted by the gun body on the gun rack."

The recoil is not only on the gun mount, part of it is on the gun body, so Gao Zhendong only discusses the part on the gun mount.

As a senior expert in light weapons, Professor Liu understood Gao Zhendong's words very quickly and was even quick to find faults.

"So you mean three bare rods? Even the buffer springs are not needed?" When it comes to taking big steps, Professor Gao has to be the one.

Generally, the tripod of a heavy machine gun has a buffer spring to cushion the recoil and reduce bounce.

Gao Zhendong nodded heavily: "Yes! The function of the buffer spring is actually replaced by the elastic deformation of the gun rack. To a certain extent, the gun rack needs to bounce up, just don't jump."

In fact, the core of the elastic gun frame is to use this "elastic deformation" in conjunction with the "firing timing" to achieve the same effect as the original rigid gun frame, or a lightweight gun frame + buffer spring.

The mount of our lightest heavy machine gun was extremely simple, to the point that it looked flimsy.

In fact, the thing is very solid, but the structure is a bit counterintuitive.

"Hiss~~~~~~Can this support the back seat? It's okay if it's lowered, but if it's raised higher, it looks like it's easy to flip over." Looking at the three bare poles drawn by Gao Zhendong on the picture, Professor Liu took a breath of cold air. This thing is light, but it doesn't look strong.

"We have to note that the main task of this machine gun is to shoot at the ground when it is laid flat. However, it is not its essential job to shoot at the sky when it is raised. If it is to be used in that way, we can either pile up some sandbags to assist, or have soldiers hold it tighter, or put it on a carrier stand. These will not affect its anti-aircraft function." Gao Zhendong said with a smile.

Oh, I forgot about that. The main usage scenario of this thing is to lay it flat or low and shoot. High-altitude shooting is not its main consideration. And the methods that Chief Engineer Gao mentioned just now can indeed achieve the corresponding effects.

"Well, what you said makes sense," Professor Liu patted his head, thinking that he was still too deeply influenced by tradition: "But is this thing strong enough?"

Gao Zhendong smiled without saying anything and drew the cross section of the tripod on the diagram: "What do you think of this structure? Is it strong enough?

"But it's still a little weak." Professor Liu made a rough estimate in his head. This cross section can indeed improve the strength, but it's still a little bit lacking.

"What if we use this kind of plate?" Gao Zhendong wrote down a series of mechanical properties data of rolled thin steel plates on a piece of paper.

Well, I forgot about this. Professor Gao, his major is actually materials. You are so great and noble. You can have any materials you want.

Professor Liu quickly estimated in his mind: "Well, this seems to be about the same, but it still can't solve the problem of the impact of ricochet on the bullet. I always feel that the idea you just mentioned is a bit too advanced." Professor Liu didn't want to say directly "You are talking nonsense", and Gao Zhendong never spoke without purpose, so he spoke more tactfully.

Gao Zhendong laughed and said, "Not ahead of the times, not ahead of the times. In fact, this elastic gun mount, which combines the firing timing of the weapon with the movement of the gun to achieve the desired shooting accuracy, is not my original idea."

What? There are still experts?

"who is it?"

"Russians, this time we are going to imitate and improve the Russian PK machine gun. Its tripod is this kind of gun mount. The gun body is also much heavier than the gun mount. We use this idea to solve the problem. When we start our work, we can ask the Defense Work Committee for some PK sample guns, which will also help us carry out the design work of 12.7."

Professor Liu was not responsible for replicating the PK machine gun, but this matter did not need to be kept secret from him. The PK's tripod was not as extreme as the PKM, but it had already shown the beginnings of an elastic gun mount.

Gao Zhendong did not take the credit for proposing the elastic gun mount, nor did he force the idea that "great minds think alike". This idea was indeed first thought up by the Russians.

"Ah? It seems like there is a way." Professor Liu did not blindly believe Lao Maozi, but Lao Maozi and Professor Gao both thought that this method could solve the problem, so it seemed that it could really work. Then he discovered a big problem: "But the law of elastic deformation is difficult for us to calculate."

Without understanding the deformation rules, it is impossible to adjust the weapon's firing rate in a targeted manner. In theory, you can try to adjust it bit by bit, but the result is hard to predict.

Gao Zhendong pointed to the computer and said, "We can consider using the finite element method and computers for simulation and analysis."

"Finite element method? What is this method?" Professor Liu was not very knowledgeable about mathematics. This emerging mathematical tool, which was born in 1943 and whose real development began in the late 50s, was beyond his understanding.

Gao Zhendong was stunned for a moment. He forgot that this was not several decades later. Now, let alone mastering this thing, there are not many people who even know about it. Even he himself only studied it in depth by specially extracting a paper on elastic gun mount design.

"It means breaking an object into small pieces for mathematical and physical analysis, while also considering the relationship and impact between these small pieces." There is no way to elaborate on this matter for the time being, so Gao Zhendong gave an example.

Professor Liu was shocked: "In this case, the amount of calculation will be enormous." He is also a professor, and when he heard the words "consider the mutual relationships and influences", he knew that this thing would require a lot of calculations.

Gao Zhendong smiled and said, "Don't worry about that. I've estimated that the latest computers are not very fast, but they are definitely not slow. And the segmentation granularity of the elastic gun mount does not need to be very fine, so it is generally acceptable."

Oh, yes, yes, this is a top computer and software expert... Professor Liu is a little nervous.

Then he became happy again and said, "This is our leader, so it's okay."

"Okay, okay, it's easy now that Professor Gao has it all figured out. If the gun mount goes this way, what about the gun body?"

Weight reduction is not just about reducing the gun frame. Although the gun frame is the main way to reduce weight, the gun body is also very important. Professor Liu saw that the indicator that Gao Zhendong came up with is not simple, so this aspect also needs to be studied carefully.

"There are too many details on the gun to be clearly stated at this stage, but there are some that we can confirm first."

"Okay, you tell me and I'll write it down and put it into the overall plan for the project application. Let's get this thing started first." Professor Liu happily spread out his notebook.

"The gun frame uses a universal ball head instead of the elevation and direction mechanism. The overall configuration is a hollow shoulder stock, a pistol grip trigger, an aluminum alloy receiver, a short recoil barrel and a gas-operated hybrid automatic principle."

Gao Zhendong began to copy frantically.

"Well, it's easy to understand that the universal ball head replaces the elevation and steering mechanism. It reduces weight and complexity. The buttstock and pistol grip are also easy to explain. It uses human power to further offset the recoil. But what's the matter with this short-barreled gas-operated gun?"

Short barrel recoil and gas-operated are two different automatic principles with completely different structures. It is extremely difficult to combine them together.

Gao Zhendong patted his head and said, "I forgot to mention that the short recoil of the barrel here actually has one main purpose, which is to use the recoil of the barrel to alleviate the overall recoil force. It has nothing to do with automatic. The real automatic method is actually gas-operated."

Our heavy machine gun is not much heavier than the S2 light machine gun. Our scientific researchers have really put a lot of thought and effort into it. They have used all possible means to reduce the recoil without reducing the power, so that the lightweight elastic gun mount can be truly used.

Lao Maozi: Actually, it doesn’t need to be that light~~~~~~
"Ah, I see. The short barrel here is just to reduce recoil and weight. But can the locking mechanism installed in the aluminum alloy receiver withstand the impact of the 12.7mm bullet?"

"No, we can do something fancy and make the locking sleeve on the barrel. If the rear of the barrel is made thicker and stronger, it can withstand the impact. The receiver itself does not need to be so strong, which can save a lot of weight."

Gao Zhendong drew a few strokes on the notebook, and Professor Liu's eyes gradually became clear from confusion.

"Great! Great! This method is absolutely perfect!" This method is not suitable for small and medium calibers such as 7.62, as it will greatly increase the size of the gun body. However, it is suitable for 12.7, as the size margin of 12.7 is much larger.

To be honest, if he had done it himself, he would never have come up with such a brilliant solution as Professor Gao's.

In order to lose weight, Professor Gao really tried every possible way.

(End of this chapter)