The most difficult thing to produce breech-loading guns with rifling is to make rifling.

Xia Xue called Xu Mo and introduced his ideas to him, and the smart Xu Mo quickly understood Xia Xue's idea, and he carried out various studies and experiments day and night. Xia Xue often saw that the other staff members were off work, and Xu Mo was still immersed in research in the workshop or office.

Xu Mo's eyes are a little short-sighted, he has a hard time seeing things, and he needs to be very close, so Xia Xue used the glass he developed to match him with a pair of myopia glasses. After Xu Mo put it on, his eyesight greatly improved, and he no longer had to bend over and look down at the drawings and equipment as he did in the past.

Xia Xue found that this shy young man always blushed when she saw her, and said in her heart: "Hehe, what a little girl!" I'm more shy and shy than a little girl! ”

Seeing Xu Mo working without sleep or food, afraid that he would be tired, Xia Xue often brought him meals during meal time, and the two of them discussed together in the office or workshop while eating.

Sometimes while eating, Xia Xue has a wit, and will personally conduct processing experiments on the machine tool, a pair of slender and slender green jade fingers flexibly and skillfully carry out various operations, and Xu Mo, who is watching from the side, often looks in a daze.

When Xia Xue processed a satisfactory effect, she would sometimes raise her head and smile at him, like a hundred flowers blooming and dazzling, and Xu Mo was fascinated. Working with a beautiful boss, Xu Mo feels extremely happy.

After repeated research by Xia Xue and Xu Mo, a rifled barrel was finally manufactured by the single-point hook method.

The single-point hook rifling method uses a hook-shaped sharpener to cut a single rifling in the barrel and the inner wall of the chamber with the same diameter. Each time you cut, the depth of cutting is gradually increased until the expected rifling depth is reached, so each rifling may have to be cut 20-30 times, which is very time-consuming and inefficient.

Later, through improvement, the multi-point broaching method was invented, which is an improvement of the single-point hooking method, using a broach, while pulling and turning, several rifling wires are cut out at the same time. In the initial experiment, the broach was broached several times, and each broach was a little larger than the previous one, gradually increasing the rifling depth; Later, after further improvement, multiple sets of die dies were designed on the same broach, and the back die was a little larger than the front one, so that the rifling could be cut out without changing the broach. The efficiency of manufacturing rifling by multi-point broaching is much higher than that of single-point hooking.

However, after all, without the electric motors, high-voltage machines, intelligent control, etc. of later generations, the production of rifled barrels is still very slow.

The requirements for the barrel are not just hard, compressive and high-temperature resistant. Another essential property is toughness, which means that the barrel must also have a certain elasticity, otherwise it may lead to an explosion. Therefore, the quality of the steel required for the production of the barrel must be good, which can be basically realized due to the relatively advanced steelmaking line built by Xia Xue, but after all, it is a special steel with relatively high requirements, and the pass rate is not very high, so the daily output of special steel required for the barrel is not very large.

After more than 3 months of hard work by Xia Xue and Xu Mo, the first rifled breech rifle was finally made. The caliber is 7.92 mm, ammunition: 7.92 mm× 57 mm, ammunition mass: warhead mass: 7.91 g, full bullet mass: 16.4 g, operation: rotary rear pull shot, ammunition supply: 5 rounds with built-in magazine, full gun weight: 3.9 kg, length: 1.1075 m, barrel length: 0.6 m, muzzle velocity: 755 m/s, effective range: 800 m.

The shape of the crosshair is "∧", and it is matched with the front sight with a dovetail groove. The ruler is a "box" ruler that can be erected, with 3 notches on it, and there are 3 ways to use it. When carrying a rifle or the target is within 300 meters, the gauge frame is used in the state of pulling forward, and the firing distance corresponding to the notch on the gauge frame plate is 300 meters; When the target is above 400 meters, the gauge frame is erected backward and the vernier is moved up, and another notch on the gauge frame plate is used to illuminate the door, and the corresponding firing distance of this notch illuminating the door is 400 meters; When the target is more than 500 meters, then make the ruler frame still stand up, move the vernier down to positioning, use the third notch on the vernier to illuminate the door, and the firing distance corresponding to this notch illuminating the gate at this moment is 500 meters; When the firing distance is greater than 500 meters, the vernier is moved up one by one, so that the gap on the vernier corresponds to the distance of the target.

In order to increase the hit rate, Xia Xue added a 2.5x scope to the Angel Rifle. Because glass has already been mass-produced, making ordinary telescopes is trivial to Xia Xue, she asked the workers to specially polish some convex lenses and concave lenses for manufacturing telescopes, with these lenses, Xia Xue quickly made several telescopes, in addition to equipping angel rifles, but also gave them to Li Jing, bearded guests and other generals for combat observation of the enemy's situation.

Equipped with a bayonet, the bayonet is 30 cm long, the bayonet is composed of two parts, the knife body and the handle, it is a separate design that can be removed from the gun and loaded into the scabbard, and the bayonet can be installed when shooting in peacetime, so as to reduce the weight of the rifle and increase the hit rate; Due to the quick and simple installation of the bayonet, the installation time before hand-to-hand combat was sufficient. The rifle bayonet is mainly used for melee white-edged combat, and can also be used as an auxiliary tool for combat operations, in addition to stabbing, cutting, cutting, sawing, but also adding functions such as cutting wires, opening cans, and screwing.

Xia Xue named this rifle: Angel Rifle.

After more than 3 months of fighting day and night, he finally made a more ideal firearm rifle, Xia Xue looked at Xu Mo, whose hair was unkempt and his eyes were a little red, and smiled happily, Xu Mo rubbed his nose and smiled shyly, looking at Xia Xue's beautiful smile like the morning light, he felt that all the hard work was worth it.

After testing, the advantages of the Angel rifle are very obvious, which can be summarized as long range, high accuracy, strong penetration and lethality, small recoil when shooting, easy to control, high reliability and high accuracy. Easy to train recruits and good at white-knuckle combat. In addition, the ammunition burns well in the barrel, producing almost no muzzle flame and white smoke, which can be used to conceal the gunner.

Although the Angel rifle is a non-automatic rifle, it can only be single-shot, and the loading and unloading of the shell must be operated manually, and the rate of fire is relatively low compared with the semi-automatic rifle and automatic rifle of later generations, but its shooting accuracy is high, and it does not waste bullets. Under the current level of production, the efficiency of ammunition production is still relatively low, if it can shoot more than 100 rounds per minute in bursts like automatic rifles, it is estimated that the angel country will soon run out of ammunition.

After testing, the Angel rifle, in the hands of a skilled shooter, can reach the level of 1 aiming shot in 15 minutes at the earliest, which is quite enough for enemy attacks of this era.

The test results of the Angel Rifle did make Xia Xue very satisfied, but the manufacturing difficulty was relatively high, and the production was very low. It took Xia Xue three months to successfully manufacture an angel rifle, which made Xia Xue very depressed, but there was no way, who made the current industrial base too poor.

Rifle bullet production is much simpler than rifle, so the manufacturing quantity Xia Xue is still more satisfied, under the current production conditions, a month can basically produce about 3000 qualified rifle bullets, but because the current rifle manufacturing speed is too slow, Xia Xue ordered the rifle bullet to temporarily produce only 1000 rounds per month, mainly to let the workers be familiar with the production process and process, so that the quality inspection personnel are familiar with the quality inspection content and procedures.

In order to increase the quantity and quality of Angel Rifle production and facilitate maintenance and repair, Xia Xue disassembled the Angel Rifle bolt into 6 parts, unified specifications, and assembly line production. In this way, the product flows like flowing water, and one person is responsible for the production of a small part, and each production unit only focuses on the work of one fragment, which can greatly improve the work efficiency and output. In order to ensure the quality, Xia Xue requires a mark on each part to count the defective rate of each worker's production.

In the end, as long as the 6 parts are assembled together, it is a complete Angel rifle, which can be equipped with the Angel Army after passing the test. Such a complex rifle has only 6 parts after being disassembled, and such a simplified design reflects the extraordinary wisdom of Xia Xue, a genius girl.

"Everything that is condensed is a high-quality product", which not only reduces the production cost, is easy to decompose, but also can greatly improve the service guarantee and reliability.