Yi Fei bought ready-made inferior fuel from the trading bank, the current price of this thing is a bit high because of the popularity of the iron axe, and a group of 100 copies is more than 30 silver coins.

The assault boat travels at its maximum speed on the sea, and the game has an autopilot mode, which saves you a lot of trouble by marking the route nodes on the chart, and the ship can automatically sail along the line to its destination.

By four o'clock in the afternoon, it took him only seven hours to return home, and he did not stop for more than 300 nautical miles.

Back on the island, everything is as usual, and no one has ever invaded the island. Yi Fei went back to the studio directly to make revolvers and fine iron axes, and this trip consumed a lot of money, but fortunately, the homemade grenades replenished a lot of funds.

After this trip to Aberia, Yifei has a development direction, rapidly expanding the number of alliances, capturing resource islands, and base islands are the future development trends.

His goal now is to take down the resource island he discovered, and to do so, he will have to speed up his upgrades and unlock more advanced weapons and equipment.

Upgrading is the easiest thing for Yi Fei, now he needs seven thousand experience to upgrade from level 17 to level 18, Yi Fei now doesn't even want to do the basic materials in order to save time, and directly buys ready-made charcoal and sulfur powder, plus iron ingots.

Another 2,000 earthen grenades were completed, and 20,000 experience points were directly sent to Yi Fei to level 20.

"Ding! Reach level 20 with +2 ATK and +1 DET! ”

After level 20, the workbench can be upgraded again, and it takes a week to upgrade an intermediate workbench to an advanced level with a thousand mechanical parts, capable of crafting three sets of items at the same time.

Yi Fei immediately upgraded the workbench, and this time he directly gained 500 points of experience, and a single research and development of the advanced workbench requires a set of mechanical parts, and if it is repeated, it can obtain 80 points of formula experience.

However, the Advanced Workbench generated a R&D preview list with only three things, in other words, upgrading to the Advanced Workbench only gave four new recipes.

The four recipes are: semi-automatic pistol, handmade explosives pack, explosives, and tin suit.

The semi-automatic pistol is the second gun recipe that Yi Fei saw when he entered the game, and the manufacturing conditions are simple, but also difficult. The first two materials it requires, the Iron Ingot and the Metal Tube, are relatively easy to obtain, but the remaining pistol body, like the mechanical parts, can only be obtained by opening a box or other means.

However, Yi Fei felt that there must be weapons in the Aberian weapon material stores, but he didn't know how expensive they were.

The Iron Suit is a level higher than the Leather Armor Suit, and the crafting materials are much more complex than the Leather Armor. In addition to animal skins, iron plates and needles and threads were added to the main materials. The production time of a single piece has changed from 24 hours to 48 hours, and the conditions are much harsher.

The formula for needlework and iron plate had already been developed at the intermediate workbench, and Yi Fei hurriedly set about changing it for himself. The tin suit is also four pieces, tin shoes, tin helmet, tin armor, and tin leggings. Each piece required thirty skins, three needles and threads, and one iron plate.

The iron plate is made of five parts of fine iron ingots and thirty parts of mechanical parts, and the needle and thread is five parts of iron ingots and ten parts of linen, relatively speaking, the cost is not high, and the whole set is about five gold shells, of which the animal skin is the main one, and now it has been fried to a group of four gold shells, the monsters in the ocean are really not easy to deal with, and the black shark that Yi Fei encountered in the sea the day before yesterday is not easy to deal with, and he will go bankrupt if he is not careful.

The ordinary iron armor suit is only 5 points higher than his perfect version of leather armor in terms of defense points, so it is naturally impossible for Yi Fei to wear the normal version. However, the upgrade of the advanced formula is exaggerated, with a fine starting point of two thousand, a high-quality five thousand, and a perfect eight thousand. It takes 15,000 experience to rise to the top, and it is 18,900 copies to replace it with mechanical parts, and the average price of mechanical parts is more than 15 gold shells in a group of eight silver shells.

"It's a good deal to upgrade at this time."

Yi Fei simply spent 400 gold from the trading house to sweep 400,000 mechanical parts and electronic components and put them into his studio, which is already five percent of the entire trading house, if he buys more, I am afraid that the price will immediately rise. Seeing that everyone is about to start getting into contact with revolvers and fine iron axes, the price of mechanical parts will definitely surge by then, and he has so much money now, and the money he will save in the future will be a lot of small amounts.

After leveling up, the perfect iron suit increases the defense point by 45 points, and the upgraded 4 points are almost 50 defense points. The suit also added an additional forty HP, and Yi Fei's HP suddenly soared to 235 points. On this set of equipment, Yi Fei is now wearing out, and when he encounters a normal version of the revolver, he stands and lets the opponent aim at the head to hit, and the double damage of deducting points of defense and damage reduction can hit at most thirty points of blood, and six bullets in one round can't put him down.

It is obviously not convenient to move after wearing the iron suit, but the current level of technology can only make this kind of equipment.

The last two things made Yi Fei very excited, a handmade explosive pack, a piece of weapon with an explosion kill range of ten meters, a minimum damage of two hundred, and a maximum of five hundred.

The handmade explosives pack is made of five parts of explosives and two parts of hemp rope and takes 3 hours to make. The cost of making this explosive is relatively high, one requires fifty parts of gunpowder, three parts of low-quality fuel oil, and ten parts of iron ingots.

Now the unit price of charcoal and sulfur powder has risen to a group of four silver shells, and according to the calculation that each group of two materials can make twenty parts of gunpowder, the price of a group of gunpowder is forty silver shells. In other words, the cost of a handmade explosives bag is already as high as 20 silver shells, plus hemp rope, iron ingots, and low-quality fuel oil, a dynamite package costs 25 silver shells, which is equivalent to making two and a half earthen grenades.

However, this is not critical, and homemade grenades are not easily detonated by factors such as external explosions or bullet hits, but explosive packs can be blasted in tandem. In terms of sneak attacks, it is much more reliable than the thunderstorm that Yi Fei imagined before.

The formula of the manual explosive pack cannot be upgraded, the fuse time is ten seconds, and it is directly detonated by squeezing or exploding, and Yi Fei feels that there is hope for eating that resource island.

Thinking of this, Yi Fei decided to do what he said, he first put the more than 2,600 earthen grenades in his hand on the trading house in batches and sold them, and then purchased raw materials.

By dinner, he had prepared two thousand handmade explosives packets, which filled the compartment storage space of the assault boat. After taking a shower and eating, Yi Fei went online on time, started the assault boat, and went straight to the resource island.

The speed of the assault boat was very fast, and at high speed, Yi Fei arrived near the resource island in half an hour, approaching the island type, Yi Fei extinguished the engine, and slowly approached a reef area where he landed last time by inertia and tide.

Nailed down the cable, Yi Fei held the simple revolver and touched it in the direction of the dock.