Chapter 144: Casting Cannons (Part 1)

"The Artillery Production Leadership Group's first meeting is now in session!"

The Mechanical Plant's office was crude but spacious, dominated by a blackboard that had been erected at one end. Weapon enthusiasts had gathered around Zhan Wuya, head of the Mechanical Group, and the atmosphere crackled with fervent debate over which type of cannon they should manufacture.

"Let me begin with introductions," Zhan Wuya said. The core members of the Mechanical Group needed no explanation—Wang Luobin, Jiang Ye, and Xiao Bailang were all present. But they had also been joined by several weapon enthusiasts whose expertise lay outside machinery: Zhang Bailin, who peppered every conversation with "cannons, more cannons" and had taken to calling himself the "Artillery General"; Wang Ruixiang, who harbored an abiding love for axes; Li Yunxing, who had designed the mechanical crossbow structures and supervised their construction on-site; Bai Yu, whose background spanned weapons design, engineering, and armored vehicle command. Finally, there was Lin Shenhe, who brought extensive hands-on manufacturing experience to the table.

The meeting's purpose was not to assign production tasks, but to determine the technical roadmap—a "Technical Roadmap Seminar," to use the proper term.

"First, let's set aside the question of whether a twelve-pounder mountain howitzer or a Type-92 infantry gun would be better," Zhan Wuya said, establishing the parameters for discussion. "We need to examine this from practical and manufacturing perspectives."

In terms of machining capabilities, the transmigrators' processing level exceeded that of every civilization in this world. Now that steel was available, manufacturing simple rifled breechloaders presented no major technical difficulties. Recoil guns did face spring-related bottlenecks, but carriage-recoil guns posed no such problems.

Even mid-nineteenth-century industrial levels had proven capable of manufacturing fifteen-inch cannons. Steel wasn't strictly necessary—many super-caliber coastal guns had been cast from iron. And since the travelers had no ironclad cruisers to contend with, they had no need to build such monstrosities.

What did the transmigrators actually need? According to staff recommendations, their priority was equipping naval vessels and gun emplacements.

"Rifled breechloaders, obviously," Li Yunxing declared. "The advantages are too numerous to ignore."

Following conventional thinking, a cannon's range should be as long as possible. But this raised a critical question: modern cannons' ever-increasing range was built upon modern observation and fire-control systems—technology the travelers, operating at a sub-late-nineteenth-century industrial level, simply could not replicate. Even the twenty-first-century equipment they had brought with them would only last so long.

A twenty-four-pounder muzzle-loading heavy gun had an effective range of no more than nine hundred meters. Mount it on a ship, and stability issues cut that range by at least half. British Royal Navy firing regulations from the eighteenth and nineteenth centuries had specified that twenty-four-pounder long guns should have a maximum range of four hundred yards—already considerable compared to the more common thirty-two-pounder large-caliber carronades. In actual combat, opposing ships often closed to within a hundred meters of each other.

Seventeenth-century cannons certainly wouldn't exceed these limits. The travelers' naval rifled breechloaders should therefore aim not for high power or long range, but for rapid fire and reduced weight. Even if rifling increased effective range, they should cap it at two thousand meters. Beyond that distance, there might be some value in land engagements, but hitting moving point-targets at sea with the transmigrators' level of fire control was essentially futile. Excessive range was pure waste.

Since range requirements weren't demanding, barrel length could be shortened, saving both weight and manufacturing costs.

Rifled breechloaders offered another significant advantage: they used pointed shells rather than round balls. Pointed shells flew far more stably than spherical projectiles. Their elongated shape allowed for rearward extension, meaning that for any given caliber, the weight could be adjusted. When comparing a pointed shell to a round ball of the same weight, the former's caliber was only about seventy percent of the latter's. In cross-sectional area, that dropped to just forty-nine percent. The practical meaning was clear: at the same muzzle velocity, a pointed shell's impact energy was concentrated on half the area, doubling the unit energy compared to a round ball. Factor in the pointed cone's lower drag, and a pointed shell's armor-piercing capability was three times or more that of a round ball of the same weight.

The implications were striking. A twelve-pounder rifled breechloader firing pointed shells—approximately seventy millimeters in caliber—using identical propellant and charge, would have an effective range far exceeding that of a twelve-pound round ball, while matching the armor-piercing capability of a twenty-four-pounder round-ball heavy gun.

A seventy-millimeter rifled breechloader with a caliber length of sixteen to eighteen was remarkably compact by any historical or modern standard. Weighing only four to five hundred kilograms, it could be mounted on three-hundred-ton sailing ships. Add recoil mechanisms, and even one-hundred-fifty-ton small vessels could carry them. Medium-sized sailing ships armed with seventy-millimeter guns would be capable of taking on British Royal Navy first-rate ships-of-the-line from the peak of the sail era.

When you considered the vastly higher firing rate compared to twenty-four-pounder muzzle-loading cannons, plus the effective range advantages, the result was clear: large sail battleships would find themselves helpless against such weapons, possibly even outclassed entirely.

In the early seventeenth century, producing such small breechloaders would be completely sufficient. Against any contemporary navy or pirate fleet, overwhelming advantage was guaranteed.

"So why not just copy the Type-92 infantry gun?" someone suggested after hearing about the breechloader's advantages. "The Type-92 has a seventy-five millimeter caliber and a maximum range of 2,800 meters—that matches the performance you described exactly. And the Type-92 weighs only 210 kilograms, far smaller than the estimated 500."

"The Type-92's problem is its caliber length—it's only six, which means low muzzle velocity," came the response. "For naval guns, you want flatter trajectories. The Type-92 is excellent for army use, but not for our purposes."

Wang Luobin proposed that naval guns could use the Armstrong gun structure, which was relatively mature and reliable while remaining simpler to manufacture. Compared to earlier breechloaders and muzzle-loading rifled guns, the Armstrong's distinguishing feature was its introduction of the screw breechblock and obturator. Remove the breechblock, and an Armstrong gun resembled a through-bored muzzle-loader. Barrel casting and machining were similarly straightforward.

The Armstrong's weakness lay in its early-type locking design, which was overly complex, unstable, and prone to high failure rates. The travelers naturally had no intention of copying it blindly—they could adopt a simple screw breechblock instead. The technical requirements weren't prohibitive; if you could manufacture screws, you could make this mechanism work.

"That sounds simple enough," Xiao Bailang said, throwing cold water on the enthusiasm, "but who here actually knows how to make cannons? I suspect everyone's just read some books. When we made the Type-92, we worked from ready-made seamless tubes. Where are we going to find tubes that thick now?"

"Casting is naturally the primary method," Lin Shenhe said. "Without large forging machines, deep-drilling requires specialized equipment. I've actually cast cannons in America—though only smoothbores."

Bai Yu spoke up. "Honestly, I'm not worried about whether we can make the cannons themselves. My concern is ammunition. I agree with everything that's been said about breechloader advantages, but one point hasn't been addressed: breechloader shells are harder to manufacture than the breechers themselves. Solid armor-piercing rounds are manageable, but what about HE shells and shrapnel? How do we make those? Pointed shell bodies require metal-drawing processes—how do we solve that? Shell fuzes are another problem entirely."

"Shell body manufacturing isn't a problem," Jiang Ye said. "Our equipment can handle it."

"Just 'can handle it' doesn't mean batch production," Bai Yu countered. "A single-bullet production line requires thirty or more specialized machines. Shells require even more. Our industrial capacity clearly can't support such production lines."

"Correct." Zhan Wuya nodded. "And materials might not pass muster either." Shell bodies—whether cold-drawn or hot-drawn—required specialized round bar stock and specialized equipment. It wasn't that the Industrial Department couldn't manage it, but it would need the support of an entire industrial system. Without that, costs would be unimaginably high.

"No, old-style pointed shells weren't that complex," Lin Shenhe said. "Early breechloader shell bodies were cast-iron, lead-wrapped, with simple impact fuzes, black-powder fills, and black-powder bags as propellant. No cartridges, no primers. Firing still relied on igniters. Most pre-1890 shells belonged to this type. They wouldn't work for the Type-92, but for Armstrong guns, they'd be perfectly suitable."

Rifled cannon shells required lead-wrapping to embed shells into the rifling—cast-iron or steel was too hard and would severely damage the grooves. Even modern shells used steel bodies with diameters smaller than the rifling's inner diameter, fitted with copper driving bands slightly larger than the bore to engage the rifling.

"But lead-wrapping has issues," Wang Luobin said. "I recall Armstrong guns being decommissioned after only brief service, with Britain returning to muzzle-loading rifled guns. Part of the reason was that firing Armstrong guns caused hot-dipped lead's poor adhesion to iron, tearing off lead fragments that scattered at close range and injured friendly soldiers."

"I don't think that's an especially serious problem," Lin Shenhe replied. "The Mechanical Department people can surely devise solutions."

He paused, then added, "Also, I personally think we should make smoothbores as well."

Smoothbores had simpler manufacturing processes and lower material requirements. If steel proved insufficient, they could use cast-iron directly. Early Armstrong-type breechloaders and smoothbores had nearly identical casting processes. Besides Lin Shenhe, nobody present had cannon-casting experience. Using simpler smoothbores to practice and familiarize themselves with casting processes seemed a wise choice.

"I suggest the Commercial Department add smoothbores to the export catalog," Lin Shenhe said. "The Portuguese are already serving as arms merchants for Ming—we can't let them take all the silver."

Note: This chapter's seventeenth-century rifled cannon casting commentary comes entirely from SANJYSAN on SB-forum. Armstrong gun explanations provided by Wang Luobin himself.

(End of Chapter)