The development of tank cannons has gone through phases from smoothbore to rifled, and then back to smoothbore.

Initially, most tank cannons were smoothbore, and the "Saint Chammon" being equipped with a 75mm cannon was considered an exception.

That was because tanks were more rudimentary, and most people perceived them as "bullet shields" without high accuracy requirements for the cannon.

However, as tank development progressed, the battlefield's demands for tank cannons grew higher, leading to the gradual adoption of rifled cannons.

Compared to smoothbore cannons, rifled cannons had several advantages: longer range and higher accuracy.

This often played a crucial role in tank battles:

When two tanks of equal distance and armor capabilities met, the accurate rifled cannon could often secure a decisive hit and emerge victorious.

This was a fatal blow to smoothbore cannons, so most tank cannons during the Second World War adopted rifling.

But everything changed completely with the advent of "fin-stabilized discarding sabot" rounds.

(The image above shows a fin-stabilized discarding sabot round. Its saddle-type sabot automatically drops off during flight, hence the term "discarding." What finally reaches the target is an arrow-shaped projectile with fins, which maintains stable flight rather than tumbling in the air.)

The rifled cannon's advantages of "longer range" and "higher accuracy" were due to the rifling inducing a spin on the shell, thus ensuring stable flight.

However, if a smoothbore cannon utilized an arrow-shaped projectile, it could achieve the same stable flight and precision.

Therefore, the advantages of rifled cannons were perfectly surpassed by smoothbore cannons, turning them into disadvantages that rifled cannons could never overcome:

Rifling was expensive to manufacture.

The rifling caused severe friction between the cannon and shell during firing, leading to a short lifespan.

The friction between the shell and the rifling consumed a lot of kinetic energy, resulting in lower muzzle velocity and weaker armor penetration.

...

In summary, compared to smoothbore cannons, rifled cannons were disadvantageous.

(Note: Nearly all countries switched to smoothbore cannons after WWII, with only Britain and its colonies stubbornly sticking to rifled cannons. Recently, Britain finally conceded and purchased German smoothbore cannons for retrofitting, but by that time, their smoothbore production technology was far behind that of other leading nations.)

Shire, understanding this developmental path, resolutely chose the smoothbore cannon.

Why go through detours when one can directly adopt the best solution?

At present, other countries did not have dedicated tank cannons, so Shire had nothing to worry about; a 75mm smoothbore cannon was sufficient.

When other countries developed dedicated tank cannons and transitioned to rifled cannons, Shire could just throw the "fin-stabilized discarding sabot" blueprints on the table:

"You are all garbage."

"All your rifled cannons are costly and inefficient. Discard them all!"

"Use smoothbore cannons with 'discarding sabot' like me, or face death!"

...

Of course, Shire wouldn't say this to Stokes and the researchers; it wasn't the right time, and it was unnecessary.

If anyone else learned and implemented such an advanced concept ahead of them, it clearly wouldn't align with Shire's capitalist interests.

Better to let all countries invest heavily in developing rifled cannons, then let them painfully abandon them after much effort.

"It's wartime, gentlemen." Shire found a perfect excuse: "You know the battlefield can't wait that long. We need to equip tanks rapidly, especially since France is severely lacking in manpower and resources, forcing us to compromise."

Stokes and the researchers were all stunned.

What Shire said was true, and they had no rebuttal.

After a while, Stokes spoke first in agreement: "The General is right. We must consider the practical use of our battlefield equipment."

The researchers nodded one after another:

"Yes, we only considered the equipment itself without considering the actual situation."

"France has implemented rationing, so producing costly rifled cannons is indeed impractical."

"If it can't reach sufficient scale, it won't have the desired combat effectiveness on the battlefield. I agree with the General's view!"

...

Thus, consensus was reached: the new tank cannon would use simple and low-cost smoothbore technology.

(Note: Modern tank smoothbores utilize more complex technology to enhance lifespan and performance, making them costlier than rifled cannons. However, during WWI and WWII, smoothbore cannons were significantly cheaper than rifled ones.)

After this discussion, Stokes led Shire and Dejoka to his office.

Shire was astonished to find Stokes' office luxurious, over a hundred square meters, divided into three rooms and a living room, with a secretary's office, a communications room, and a workshop, all fully equipped, even with fitness equipment.

Shire gave Dejoka a puzzled glance; this far exceeded his own office's specifications.

Dejoka nodded slightly, with a smile in his eyes, seemingly saying: "Only this can retain talent, and it's worth it!"

There was a hint of helplessness on Shire's face; he wanted to say: "Father, Stokes is basically a 'traitor'; you don't need to worry about not being able to keep him."

Stokes warmly invited the two to sit on the sofa: "What would you like to drink?"

Shire ordered coffee, Dejoka ordered wine, and Stokes himself also asked for a glass of wine.

Soon the secretary brought them beverages, along with a platter of sliced apples and pastries.

These were not easily obtainable for an ordinary family during the rationing period.

"Your son is excellent, Mr. Dejoka!" Stokes smiled and clinked glasses with Dejoka, complimenting: "He solved a critical issue in just a few sentences that we had debated for days without resolution."

"Thank you, Mr. Stokes." Dejoka graciously accepted: "He is indeed remarkable."

Shire didn't say much, he took a blueprint from his briefcase and handed it to Stokes: "Can you produce this, Mr. Stokes?"

Stokes took the blueprint, and an unexpected look flashed in his eyes: "A cannon? Why don't you give it to an artillery factory? I'm sure they can produce this cannon..."

"This isn't an ordinary cannon, sir," Shire replied.

It was an Oerlikon anti-aircraft cannon, which could be modified for aircraft use.

"We have a similar weapon," Shire explained. "It's called the Becker Cannon, which we captured from the Germans. I need you to modify it according to the specifications and data on the blueprint."

Saying this, Shire handed another document to Stokes, which had the image and data of the Becker Cannon.

Stokes understood instantly with an "oh".

This was indeed their expertise!

He compared the two blueprints for a while, then confidently accepted: "No problem, this doesn't look too difficult!"