The TAG-3K is the standard assault gun used by the Royal Army of Siva, it's name standing for "Tracked Assault Gun", and the "3K" representing the muzzle velocity of its gauss cannon, firing at just over 3,000m/s.

While antigrav technology exists for much larger vehicles (massive warships and some aircraft), the hardware required for its use is enormous in size and unrealistic for use in ground vehicles on Siva, and many of its colonies in the Zaket system. Therefore, tried and true tracks and wheels are still used for tanks, armored cars, and assault guns like the TAG-3K. Moreover, much of the power that would be needed to provide electricity to antigrav ground vehicle technology (in the case of this assault gun) is already taken up by the rechargeable batteries in the TAG-3K that power the 100mm gauss cannon. The magnetic coils that propel the projectile cannot be seen in the image above, because of the armored sheath encasing them around the barrel of the gun.

Ribbed armor plates on the front of the vehicle also double as solar panels that help recharge the batteries from the intense light of the binary Zaket suns. Because it uses such an immense amount of energy to fire the weapon, it carries enough stored electric charge to provide firepower for the 40 rounds of highly magnetic samarium-cobalt core tungsten ammunition carried onboard. In low light conditions or in evening, the highly efficient biodiesel engine can also assist in recharging the batteries.

The batteries also help keep up the deflector shields around the vehicle, which are effective against plasma and laser weaponry but can be weakened through continual fire. Kinetic and ballistic weapons of a large enough caliber can ignore the deflectors entirely, but still need to penetrate the sloped armor plates, composed of a nickel-vanadium-iron alloy nearly 8 inches thick at the front (9 inches if including the inch of depleted uranium armor sandwiched at the halfway point), 3 inches on the sides, and 1 inch on the rear.

In conventional warfare, the 100mm projectile is medium sized and would otherwise only be capable of piercing light and medium tanks, but the penetrating power comes from the hypersonic speed of the rounds fired by the TAG-3K. The size of the round, coupled with the magnetization of the projectile, can punch through the thickest tanks as if they were made of paper, and the speed of impact can also decimate soft targets in a fire support role. The samarium-cobalt rounds, which are electrically charged as they leave the barrel, are capable of punching through deflector shields that kinetic, laser, and plasma weapons would otherwise struggle to pierce.

Some of these assault guns, such as the model you see here, have retractable dozer blades on the lower glacis to assist in pushing aside rubble and obstacles in more urban environments.

The TAG-3K is crewed by three Sivathi, consisting of a commander (who doubles as the radio operator), a driver, and a gunner. An autoloading system is implemented inside the vehicle to eliminate the need for a fourth crewman to serve as a loader, as space for an additional occupant isn't feasible inside the assault gun's already cramped interior.

Over 25,000 TAG-3K's have been manufactured in the last century, withstanding the test of time due to its effectiveness and a peak in the technological capability of the Sivathi race. Though light, medium, and heavy tanks of more specialized roles also serve alongside the more numerous assault guns, the effectiveness of the vehicle's gauss cannon on both soft and heavy targets have made it prioritized in Royal Army inventories.

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This is a sci-fi version of the Swedish Stridsvagn 103 that I found on Yeggi (an anonymous source created the 3D model for it, which was available for public download and I printed in my Elegoo Mars resin printer). I gave it a freehand digicam desert camo paintjob. Hopefully this is a vehicle that you'll get to see in the story of The Twin-Pronged Crown once it starts to get fleshed out more!