Improve it.

In the next two days, Shi Yiwen and Zhao Shizhen carefully studied the "electric gun" together.

The first thing that needed to be addressed was the airtightness, although it leaked less gunpowder gas when firing than expected. However, it still had an impact on the range.

In order to solve the problem of air tightness, in terms of processing technology, there is naturally no room for improvement by the standards of this era, unless Shi Yiwen takes them into the space and processes them with modern machine tools. Finally, after thinking about it, I added a cowhide ring in front of the sub-gun in order to increase the airtightness as much as possible. Although the effect is not as good as rubber, it can still play a little role.

In addition to this, there is the need to increase rifling.

Rifling, anyone who knows a little about weapons, knows what rifling does. The rifling can be said to be the soul of the barrel, and the role of rifling is to give the warhead the ability to rotate, so that the warhead can still maintain a given direction after being discharged.

The addition of rifling to the barrel is not very novel, as early as a few decades ago in the days of arquebuses, rifled guns were already available, except that at that time the rifling was straight, and the main purpose was to facilitate the front loading of the projectile. Soon the spiral rifling was developed, and the advantages of the rifled gun compared to the smoothbore gun were obvious: the firing range was large, the accuracy was high, and the rifled gun could accurately hit the target at a distance of two or three hundred meters compared to the smoothbore gun with an effective firing range of no more than 100 meters.

The benefits of rifling are obvious, but historically, it has never been popularized, not because of the difficulty of drawing rifling, after all, whether in North America or Europe, hunters use rifled guns, and the biggest problem with its failure to spread is the difficulty of loading. The reason why rifled guns can shoot far and accurately is because the bullet needs to rotate along the rifling before it is discharged, which requires the bullet to be embedded in the rifling. This also caused the difficulty of loading, and even had to use brute force to hit the bullet to deform it into the rifling, and even exaggerated to hammer it in, although the problem was later solved by wrapping the leather with the bullet, but its reload was still much slower than the smoothbore gun, or even intolerably slow, so it was only a small scale of equipment in the army for a long time, only used for sniping.

However, for the rear-loading "electric gun", there is no such concern, it is a rear-loading gun, naturally there is no need to consider problems such as wrapping leather, only need to manufacture a bullet that fits the caliber, it is enough to meet the needs.

However, in order to have rifling, it is necessary to build a rifling machine first.

"Get the rifling out!"

After the stun gun was called, looking at the smooth and bright barrel, Shi Yiwen muttered to himself.

Perhaps, in the eyes of many people, the manufacture of rifling is a very mysterious process, and even requires the most complex and sophisticated equipment, but in fact, for engineering students, this is not complicated, and there is a "internal spline processing process" in metal processing, which is the same as the process of drawing rifling. For rifling, it is simple to design a clever broaching machine that combines both reciprocating and rotating movements to a special broach.

It only took one day for Shi Yiwen to take out the drawings needed for the rifling broaching machine. The structure of the purely mechanical broaching machine is very simple and does not require a hydraulic press.

A steel plate that acts as a guide, a fixed barrel clamp, a broach table that moves back and forth along the rail. Together with a connecting rod that turns the rotation of the circular turntable into reciprocating motion, the original mechanical broaching machine is formed. The round hand-cranked turntable can be connected to the hydraulic drive shaft with a belt, even if it can be done by human means. In this way, mechanized production can be realized, which of course is not needed now.

The only difficulty is how to make the broach rotate, and the same as the requirements in the internal spline processing process, the barrel must be fixed in the processing process, and the rifling of the processing rotation only allows the broach to rotate, and in the internal spline processing process, there is also a method of processing the rotating internal spline, only need to add a gear behind the broach, a section of gear guide rail, and the guide rail that is inclined at a fixed angle is connected above the gear guide rail. In the reciprocating motion of the broaching machine, under the effect of the upper inclined guide rail through the gear guide rail, the guide rail is moved up and down to drive the rear gear of the broach to rotate, so that the broaching machine of the required reciprocating and rotating two motion modes is also obtained.

The principle is very simple, anyone who has been in contact with the internal spline processing process knows its principle, all that is needed is to replace the hydraulic press that pushes the broach with simple mechanical energy.

Compared with the design, the manufacture of rifling broaching machine is undoubtedly more time-consuming, such as steel plate and other materials, all of which are taken from the space by Shi Yiwen. Even so, it still took three days, and its practical wrought iron or thickened cast iron would work, but Shi Yiwen was not willing to waste too much time.

Three days later, standing on the shooting range -- a thick wall with sandbags -- 100 meters away,

Aim, adjust breathing, pull trigger......

With the crisp sound of the flint hitting the fire platform, the moment the fireworks rose to fat in the fire platform, there was a "bang", and the gun body slammed back down, hitting Shi Yiwen's shoulder a little numb, and a white cloud of gunsmoke poured out of the muzzle.

Almost at the moment when the gun rang out, Zhao Shizhen ran forward from the side, ran to the wooden target in front of the sandbag at the base of the wall, looked at the target, and a hole was punched in the wooden board, and he immediately shouted loudly.

"Hit, hit......"

There are only target plates, no ring targets, and even the target board is 6 feet high and 2 feet wide, which is about the size of a human figure. According to the "factory standard", "Thunderbolt" can hit nine shots in 20 zhang, ten shots, and hit the target even if it is qualified. Such a standard is simply outrageously low, but it is also the "high standard" of this era.

Now, it is definitely not possible to test a rifled gun with such a target, after thinking about it, Shi Yiwen asked people to take a piece of paper and a compass, and the factory apprenticeship class has begun to use tools such as compasses and rulers, all of which Shi Yiwen brought out from the space.

When Shi Yiwen was making target paper, Zhao Shizhen was puzzled.

"What's going on?"

"Target paper, specifically for testing accuracy."

Without waiting for the ink and sweat on the target paper to dry, Shi Yiwen had people nail it to the target, and then puffed down the butt of the gun, and at his suggestion, the "stun gun" had become a long gun, as for the short gun...... Just use a few sticks.

At least not yet.

Aim and shoot again......

When Zhao Shizhen ran to the target again, he stared at the target for a while, and only when Shi Yiwen shouted, did he reply loudly.

"Eight...... Eight rings. ”

Isn't this the legendary "100 steps through the Yang"!