Chapter 70 - About Rifling

Thinking of these questions in his mind, Ye Qing couldn't help showing a trace of melancholy.

The plans are beautiful, and the equipment is bought. If once, the porcelain clay produced by the system fails to meet the barrel material standard, Ye Qing will really want to cry.

The first pot of gold he earned was all smashed in. Failure is not a complete failure, but it is no better than returning to the pre-liberation period.

But as the saying goes, there is no turning back arrow in the bow. Having already reached this point, Ye Qing has no retreat.

Having gone out to dig for cover yesterday, Ye Qing now has no worries in the studio to exchange a piece of china clay directly from the system. Then began to make embryos according to the barrel size of the P238 pistol.

There are several processing methods for rifling, but no matter which processing method, you need to drill the barrel first. Because of the particularity of porcelain, Ye Qing can directly knead tubular porcelain with holes in the middle.

Due to the shorter barrel size of the Xiuzhen pistol, six barrel embryos were made from a piece of china clay leaf green foot. The next step is to burn these embryos into semi-finished ceramic barrels.

Three hours later, the firing of the ceramic barrel was over. Leave the semi-finished barrels in the kiln to cool naturally, and Ye Qing walked back to the store. While thinking about replacing the brick kiln with an electric kiln if it succeeds, I made myself a late lunch to treat the five internal organs temple that is in the uprising.

Eat and drink, and then come with a cigarette after a meal that has beaten the living gods. Take a short rest and enjoy the ease of autumn afternoon. Ye Qing became busy again.

Well, it's not too busy to say it's busy. Now the barrel was still cooling, Ye Qing just went to study the rifling machine sent by the CIA.

When it comes to barrel rifling, most people are familiar with it. Rifling is also called Rifle, and its earliest history can even be traced back to the 15th century. However, due to the limited production conditions at the time, there was no wave in history.

Beginning in the 19th century, rifled guns replaced muskets. Rifling has become an indispensable part of firearms.

In the barrel, the concave part is called the Yin line, and the convex part is called the Yang line. Speaking of this, Ye Qing remembered something very interesting, and that was the issue of standards.

Generally speaking, the caliber we are talking about refers to the distance between the Yang line and the Yang line. However, there are always those fancy guys who like to measure the distance between the Yin line and Yin line. For example, the .38 caliber and .357 caliber that Ye Qing is about to pull are actually the same caliber, maybe the length of the warhead is different. But the bullet diameter of these two calibers is absolutely the same.

In addition to the caliber, there is no fixed value for the number of rifling in a gun. From the 2 rifles of the M1903A3 rifle at the Springfield Arsenal to 22 of the so-called Micro Groove of Marlin. The number gap has reached 11 times.

But Micro Groove, a frenzied thing, has no practical value, and ordinary guns don't need such an exaggerated number of rifling.

However, how many rifling lines are needed for a gun depends mainly on the force conditions on the deflector side. Generally speaking, the compression stress on the deflector side should be between 1/4 and 1/2 of the allowable stress of the barrel material. Different factories and countries have different requirements for this indicator.

We all know that the function of rifling is to rotate the warhead. And what makes the warhead rotate? The answer is steering force. When the warhead contacts the rifle, it will produce an extrusion stress on the side that first contacts the rifle. The product of this extrusion stress and the contact area is the steering force.

Once the extrusion stress is too large, you want to maintain the original steering force. There are only two ways, one is to increase the height of the rifling, and the other is to increase the number of rifling.

As mentioned earlier, the caliber of weapons and ammunition generally refers to the distance between the sun line and the sun line in the barrel. Moreover, the height of the rifling is suddenly increased,

The bending moment at the root of the rifling will increase. Structural strength, fatigue strength and air tightness will be severely affected. In this way, the method of increasing the height of the rifle is naturally useless.  The only way out is to increase the number of rifles and increase the force-bearing area. This is why different guns have different rifling.

In Ye Qing's motherland, the 95 and 03 rifles generally have 4 rifles. The weapons on the NATO side are mostly six rifled lines. When looking at this data roughly, Ye Qing seemed to understand the guys who sprayed the 95-style rifle on the forum before the Federal AR. After all, a gun with more rifled lines will have a much longer barrel life, not to mention others.

But after studying in depth for a while, Ye Qing found that he was wrong again.

The root cause of this phenomenon is still the difference in bullets. NATO weapons mostly use SS109 rifle bullets, also called 5.56*45mm NATO rifle bullets. The actual performance of this bullet is not very different from Ye Qing's motherland's 5.8mm rifle bullets. They are all small-caliber rifle bullets. It's basically the "big brother don't talk about the second brother" relationship.

But after all, they are two different bullets. The chamber pressure of SS109 rifle ammunition is much higher than that of domestic 5.8mm rifle ammunition, generally around 380 MPa. The 5.8mm rifle is generally less than 300 MPa.

In addition, Ye Qing also found another difference between the Ar15 and 95 foreign trade rifles and UU reading www.uukanshu.com 97 rifles. That is the difference in rifling distance.

The rifling twist refers to the degree of rotation of the rifling. The longer the distance the rifling takes to complete a 360-degree rotation in the barrel, the slower the winding distance, and vice versa. For Ar guns, the wrap distance is generally only 178mm, which is much faster than that of the 95-style rifle.

The difference in the bullets used, coupled with the difference in the design concept, has caused the difference in the number of rifling between the two weapons. This is not a basis for judging that the Type 95 rifle is inferior to the Ar series rifle.

Besides, the Type 95 rifle is not impossible to achieve 6 rifling. However, comparing the cost of increasing rifling to the improvement of gun performance, it is simply a loss to grandma's family.

After thinking about all these messy things, Ye Qing focused on his own rifling machine. Through this device with a top cone-shaped thing that looks like a rifle line, it is not difficult for Ye Qing to judge this device used to implement Button Rifling method to produce rifling.

Button Rifling is literally translated as button rifle, so this production method is also called button type. This production method is also very simple. A button-like object with a shape opposite to the rifling is squeezed through the inside of the barrel to produce rifling through high pressure. However, until now, the button shape is gradually replaced by the top cone shape.

This production method cannot be considered good, but it cannot be considered bad either. Although high-precision barrels are generally made of pull-cut and cut-cut styles, pistols don't need high-precision barrels?

Furthermore, compare the other two production methods. Button Rifling is more convenient and more suitable for Ye Qing's current small workshop...