Not daring to stay on Phantom Island for too long, after recovering his body and making a slight breakthrough, Zhang Fan took Xia Yumeng's aircraft powered by the fuel in Qiankun to set off while it was still dark, and flew a distance of about 18,000 kilometers in about half a day and night to return to Lintian City.

Using the craftsmen and even the hydraulic manufacturing equipment there, Zhang Fan didn't take too long to create a coil cannon with a structure that was not too complicated, and the improvement of intelligence and even memory brought by strong spiritual power, as well as the ability to accurately measure objects, made it seem that mechanical processing and metallurgical assistance without too much force were much easier. However, when actually using this "electromagnetic cannon", Zhang Fan couldn't help but be disappointed.

Even if the shell weighing only about 10 kilograms was used in the initial test, Zhang Fan desperately used the internal force with aura to urge the power generator motor to rotate, but he could only make this so-called "shell" launch at a maximum speed of sound more than twice the maximum, and the power was only equivalent to the tank gun of the World War II era, and the difference between the power of the chemical energy artillery of the Shenwu artillery array was simply 108,000 miles. This also made Zhang Fan feel why the "electromagnetic cannon" that appeared earlier than the smokeless powder launcher did not even replace black powder in the 19th century. Obviously: a good storage device and a device system that can discharge a large amount of electricity in a short period of time is probably the biggest technical problem for oneself about electromagnetic guns, as for the material or something, because the existence of super-grade steel on this plane is not too much of a problem.

After thinking for a while, Zhang Fan began to use the small storage power station-type hydro turbine prepared by Lintian City to generate tribostatic electricity, and tried to use his very weak current with a trace of spiritual power at the electrostatic output end to collect electricity.

At this time, the miracle that Zhang Fan hoped for finally happened. Under the control of its own internal force with a hint of aura, more and more electrons gathered together, forming a hot and bright charged ball, like a ball lightning the size of a soybean.

Zhang Fan did not give up at this time, but patiently continued to gather electricity, and the bright electric ball continued to change from the size of a soybean to the size of a fist. It was at this time that Zhang Fan felt that the electric ball seemed to be slightly unstable.

The internal force with the aura began to be able to manipulate the electric ball to approach a large tree fifty paces away, and a few seconds later, an unimaginably violent explosion enveloped everything within a radius of more than ten zhang. The power of the bright ball lightning, which was about the size of a fist, seemed to be far beyond his imagination, and under such an explosion, the tree and its roots seemed to have completely disappeared into thin air. Even at a distance of about fifty paces, if not similar to the explosive effect of modern explosives weighing three or four hundred kilograms. If it weren't for the fact that Zhang Fan and even Xia Yumeng and others were no longer ordinary people, even if they were about fifty steps away, they would probably be seriously injured.

Of course, Zhang Fan soon discovered the shortcomings of this "thunderball technique": the movement speed of this thunderball seems to be limited, and it seems that the speed of the sound is already the limit, and this is still the speed that requires a certain acceleration time to fly out. If this is the case, there is no doubt that the actual combat effectiveness will be greatly reduced. When Zhang Fan used this kind of electric ball controlled by the internal force of the aura to release the power of the electromagnetic cannon, the cannonball of about ten kilograms finally flew out at a speed that he could not imagine. According to the general perception of his spiritual power, it is estimated that there is at least a muzzle velocity of about twenty-five times the speed of sound, a speed of about eight kilometers per second, and the power is also beyond the previous single cannon of the Shenwu artillery array. And there is no doubt about it: with the same energy, a faster muzzle velocity can make the actual combat efficiency higher, and the opponent will have more difficulty escaping.

According to Zhang Fan's rough estimate, in terms of the undodging effect: an electromagnetic cannon with an initial velocity of about 8 kilometers and a power of about 300 million joules has an actual combat effect equivalent to the effect of 16 artillery arrays with similar power, and it is slightly stronger than the previous attack ability.

Zhang Fan also wanted to try again to see if he could further increase the combat effectiveness by reducing the weight of the shells and increasing the speed. However, in the virtual design deduction of the Qiankun shield: when the speed of the arrow-shaped shell reaches about 12 kilometers per second, even if the design considers the wind resistance ability, the slender armor-piercing body begins to deform due to the strong air resistance, not to mention the penetrating power, and the accuracy begins to be greatly reduced in the first place. Often flying less than two kilometers away, because of the loss of forward stability, because of the armor-piercing body sideways, but it is completely deformed under the huge air pressure.

Zhang Fan tried to further design the entire "armor-piercing body" shell, however, about 12.8 kilometers per second and about 40 times the speed of sound seems to be some kind of limit, and at this time, the effective range will be reduced to a distance of less than one kilometer, and more than one kilometer will cause serious energy loss due to wind resistance. Even if a four-kilogram metal rod is stretched to the size of an iron bar, it is not a big problem according to deduction. Obviously: the confrontation with the master of the foundation building, about a tenth of a second, I don't know how many steps can already make the opponent dodge a few steps, and the real confrontation is likely to be carried out at a closer distance?

Of course, Zhang Fan felt that this was not enough, and began to try to install a "plasma warhead" on the "electromagnetic armor-piercing projectile" like an iron spear, and finally succeeded after many experiments in the virtual environment of the shield.

In the end, Zhang Fan completely abandoned the original power and configuration, and boldly used a special container to contain a lot of plasma with a further reduction in the temperature of the positive charge, so that the energy during launch could become more powerful, and it could also accumulate a lot of energy in advance before launching.

In this way, the specifications of the shell can be re-enlarged to about 60 kilograms, the muzzle kinetic energy can reach 5 billion joules or 5,000 megajoules, and the original energy will be close to the whole of the original fire in one launch, and the shell can also be equipped with a special "plasma warhead" to make the warhead power reach about one ton of modern explosives. At the same time, due to the large number of charges in the warhead, this shell seems to have a certain tracking effect when approaching a target that is not connected to the ground in the general air, which undoubtedly makes the power increase a lot compared to before. However, Zhang Fan faintly felt that all this could be carried out relatively smoothly, perhaps because the physical rules of this plane and even the properties of electrons are not completely equivalent to the earth, but have been simplified to a large extent?

According to Zhang Fan's rough estimate: Compared with the previous set of 16 launchers of the "Shenwu Artillery Array," the muzzle velocity of the new "Shenlei Artillery" of more than six times will bring about 40 times the increase in combat effectiveness. In terms of the area of the attack, Zhang Fan roughly estimated: even if the final error with the target center accumulates three feet, it will achieve a direct hit-level attack effect within a radius of three feet and a radius of about two meters because of the violent explosion and even the weak tracking effect, and the hitting ability will be increased by at least thirty times. If you add to this the liberation brought by using only one electromagnetic cannon instead of operating more than a dozen cannons at the same time, then in the case of using this unique divine thunder cannon, your theoretical combat power should be equivalent to the level of the outer gate fifty grades, approaching the peak of ordinary or upper-middle level foundation building, and you should also have a great ability to protect yourself on the boundless continent.

This is not yet calculated: the meager aura of the West Sea Continent has undoubtedly brought a lot of trouble to its own gathering and use of electricity. If in the Boundless Continent, where the aura is more dense, a lot of trouble in using this kind of artillery array can be greatly reduced, and there will still be a lot of room for improvement in one's combat effectiveness.

After these design and test preparations were made in the virtual fantasy space of the shield in Qiankun, the preparations in reality in Lintian City were also quickly carried out. It was just a trial to produce three "Shenlei Cannons" and even Ruo** bullets, which was much easier than the original manufacturing of Shenwu Artillery Array, and did not continue to waste too much time on Zhang Fan.

When it was finished, Zhang Fan looked at Xia Yumeng, who was already in his forties and had a good appearance, and sighed: "Now we can hurry up and go to the Boundless Continent, and go to Phantom Island again to search and see if we can get any opportunities." It is said that after the monks of the False Dan realm are destroyed, they should have a unique inner pill, which may help Meng'er enter the transformation realm in advance, even if she can't change from her middle-aged appearance back to the state of a sixteen or seventeen-year-old girl, she will look much younger. In that case: perhaps we will have a lot more opportunities on the Infinite Continent, and many things will be much easier ... ”

Hearing this, Xia Yumeng was also somewhat moved, the Lord finally really called himself a "dream", and he didn't mind elevating himself to the same level.