French defense contractor Nexter has reportedly been testing a modified Leclerc main battle tank with a massive 140mm main gun as part of the development of a future Franco-German tank, known as the Main Ground Combat System, or MGCS. For decades, France, as well as Germany, among many others, have considered adding bigger cannons to its tanks to improve their armor penetration and range capabilities, but have repeatedly decided not to do so. So, it still remains to be seen how seriously they’ll pursue this course of action now. Jane’s 360 reported the news, which the outlet had learned at the International Armored Vehicles (IAV) 2019 conference in London, on Jan. 24, 2019. The up-gunned Leclerc has fired more than 200 rounds successfully and Nexter claims the weapon is 70 percent more effective than existing NATO-standard 120mm tank guns. The MGCS program, which began in 2012, aims to replace France’s Leclercs and Germany’s Leopard 2 tanks with a common design by 2035.

It is unclear if the Leclerc configuration that Jane’s is referring to is materially different from the one that first emerged in 2016. “This is understood to be the first time that a 140 mm gun has been successfully integrated onto a 50-ton MBT [main battle tank],” according to the story, but this could be a reference to a development program that has now been ongoing for multiple years. French defense company GIAT, which subsequently transformed into Nexter, first proposed mounting a 140mm gun onto the Leclerc back in 1996, four years after the tank first entered French service. The company specifically developed an enlarged turret to house a gun of this caliber that France’s Arsenal de Bourges had developed. The French military passed on this T4 turret and it went into storage. Circa 2015, Nexter reportedly reinstalled in onto a chassis that had belonged to a turretless Leclerc MARS armored recovery vehicle. It is pictures of this combination, dubbed Le Terminateur, or The Terminator, which first appeared in a French magazine two years later. Since then, additional images of the tank, now wearing a hard-edged tan-green camouflage scheme known as Scorpion have also appeared online. Regardless, the testing of the gun does point to renewed interest in a larger caliber main gun the final MGCS tank design. In 2016, Germany’s Rheinmetall, which is working together with Nexter on the Franco-German vehicle, also publicly displayed a 130mm gun at that year’s Eurosatory military trade show in France. Rheinmetall had previously worked on a 140mm design, as well.

Rheinmetall Rheinmetall's 130mm tank gun. Note the difference in the size of the ammunition, at left, compared to a standard 120mm round.

A reported requirement for the MGCS is for its gun to be at least 50 percent more capable than the existing 120mm types on either the Leclerc or Leopard 2. A larger 130mm or 140mm gun would certainly offer improved range and armor penetration capabilities. The driving force behind this demand appears to be, at least in part, the appearance of Russia’s T-14 Armata tank, which features an improved 125mm 2A82-1M main gun with more capable ammunition. The 2A82M-1M is apparently sized to fit in the same space in a turret as the older, Soviet-era 2A46 125mm gun, meaning that it could potentially be an upgrade option for Russia’s existing designs, such as the T-90. There have also long been reports in Russian media that the Kremlin is considering adding a larger 152mm main gun onto the Armata, as well, which could out-gun existing NATO tanks and their 120mm guns.

Iliya Pitalev/Sputnik via AP Russia's T-14 tank.

China has reportedly been testing larger caliber main guns, as well. So far, though, none of these Russian or Chinese efforts have led to an actual operational design. There are also very real questions about how much the Kremlin can even afford to modernize its tank fleets, at all. While a new 130mm or 140mm gun certainly offers a counter to these developments, real or not, it is not without its drawbacks, too. The most immediate issue is the size of the rounds, which will be bigger than their 120mm counterparts and require larger ammo storage options within any future tank. The 140mm-armed Leclerc, with its enlarged turret, reportedly still requires two-piece ammunition, with the shell separate from the propellant. Even then, it can only hold 31 rounds, nine fewer than the standard version of the tank.

Wikimedia A standard Leclerc main battle tank.