M723 Kangaroo

The M723 infantry support vehicle, nicknamed the Kangaroo or simply the Roo, is an infantry fighting vehicle in service of the UNSC Marine Corps.

Armament
The primary armament of the M723 Kangaroo lies in four M101 smoothbore autocannons, mounted on a large turret at the rear of the vehicle. These fire the 45x270mm shells, which are well-suited to defeating the armor of light fortifications and medium vehicles. Each gun is able to fire 32 rounds per minute, for a total barrage of 128 across all four cannons. The turret is on an elevating platform, which allows it to be sunk somewhat deeper into the vehicle to decrease its target profile while moving, and extend the turret's traverse from 10 degrees to 45 degrees escalating. Although disembarking is possible while the turret is lowered, the low ceiling clearance makes this an uncomfortable affair.

The 45x270mm is an evolution of the 40x180mm shell, and exhibits much higher velocity, greater destructive power, and further range over its smaller predecessor. Originally designed for anti-aircraft duties, it has instead seen far greater adoption among ground forces. The autoloader in the Kangaroo's turret is able to easily change between multiple ammunition types with little issues, so while High Explosive, Anti-Tank (HEAT) is preferred by most operators, it is not uncommon to see it accelerating a variety of Armor-Piercing, Fin Stabilizing, Discarding Sabots (APFSDS), High Velocity Armor Piecing (HVAP), or High Explosive AirBurst (HEAB) shells. However, the 45mm remains fairly obscure, so following the M723B model the Kangaroo is also backwards-compatible with existing 40mm shells.

To protect it against infantry, as well as offer further suppressive fire capabilities, two pintle turret hardpoints are fitted on each side of the Kangaroo. These are open-seated positions, similar to that on the M808C Scorpion, and what weapons are fitted are strongly informed by mission requirements. Most commonly, the M247H machine gun is typically fitted, which is chambered for 12.7mm .50 cal rounds and is used for anti-infantry defense. Another common choice is the M460 automatic grenade launcher, which fires 40mm timed or trigger-linked explosives at aggressors. Although primarily intended for use against vehicles and as indirect fire support, the M460's grenades can release a strong EMP that can significantly damage shields or temporarily cut power to generators and vehicles. A hybrid combination of both weapons is not uncommon, but only the grenade launcher is able to fire at both sides of the Kangaroo.

In some variants, the Marines carried aboard may have access to armored gunports, which allows them to use their firearms to directly complement the Kangaroo's firepower. However, this is not a universal upgrade, as the gaps makes the vehicle's armor more likely to crack and break apart. In addition, it also makes them vulnerable to chemical weapons.

Defenses and Countermeasures
To protect it from incoming fire, the M723 Kangaroo is plated with between 8 and 17mm of composite plating, which mixes titanium alloy with graphene-ceramic plates to keep the armor strong without making it brittle. Some plates, such as the armor skirts beside the two rear wheels, have hydraulic supports to better diffuse and defeat kinetic penetrators.

The Kangaroo has a number of active defense systems aimed at better confusing or jamming any threats the onboard computer detects.