The 2S25 Sprut-SD is a self-propelled russian tank destroyer or light tank developed. It weighs 20 tons and has a 125 mm smoothbore gun. Its main armament, the Sprut anti-tank gun, is capable of firing APFSDS, HE-Frag, HEAT and ATGM ammunition. This allows the 2S25 to be as powerful as a main battle tank and as maneuverable and amphibious as airborne infantry combat vehicles. The 2S25 can be used by units of ground forces and naval infantry as a light amphibious tank. Currently, the only operators of the 2S25 are the Russian airborne troops with 24 of these vehicles in service.
A modern autoloader for a 120–125 mm caliber weapon in good condition can achieve about 10–12 rounds per minute. This rating may or may not include the time required to bring the gun to the appropriate loading angle (if required) and then bringing it back up to firing angle after loading. This is fast, but not quite as fast as a human loader, for which claims of 15 rounds per minute (at least for a short time) are made. On the other hand, the very newest autoloaders claim to match this rate of fire. Furthermore, it is considered atypical to engage more than a few targets per minute in a tank. The autoloader may also have an advantage while travelling over rough terrain that may jar a human loader enough to disrupt his loading cycle.
For weapons above 127 mm, the increased weight of the round pushes this issue decisively in favor of the autoloader. For self-propelled artillery with calibers of around 155mm, for example, autoloaders can typically achieve 8–12 rounds per minute, while a human loader(s) can typically achieve 4 rounds per minute.
Part of the fictional bolo history
This will be the realization of Keith Laumer's science fiction Bolo tank series.
MARK I BOLO (2000):
The Mark I Bolo was an early twenty-first century update of current Abrams technology armed with a single turreted main gun (150mm; 1,722 mps muzzle velocity) capable of defeating any existing vehicle's armor (including its own) firing DSFSLRP (discarding sabot, fin-stabilized, long-rod penetrator) rounds. The Mark I carried secondary-turreted point defense/anti-personnel gatlings with on-mount radar and computerized fire control packages, required a conventional four-man crew, and relied upon a pair of high-efficiency, fossil-fueled turbines for power. Combat radius was 1,000 kilometers with a battle weight of 150 metric tons. Maximum speed was approximately 80 kph (road). The Mark I was replaced in production fairly quickly by the Mark II under the pressure the new arms race exerted on R&D as the traditional world order slipped towards general collapse.
MARK II BOLO (2015):
The Mark II was an updated Mark I, with greatly improved onboard computers and the same main armament, but with the first light lateral infinite repeater armament (four railguns in two two-gun batteries). Fitted with gatling and counter-missile point defense. First durachrome armor (10 millimeter) capable of defeating any weapon short of the Bolo's own DSFSLRP round. Electronics were designed to allow a single crewman to assimilate data and operate the entire system, and weight rose to 194 metric tons. The Mark II's fossil fuel power plant drove electric generators rather than powering its drive train directly, and the vehicle had a limited (12-hour) backup power supply of ionic batteries. The Mark II could also operate on electrical power from a secondary source (such as local civilian generator capacity) to maintain long-term readiness in the area defense role. Maximum speed was approximately 80 kph (road) to 30 kph (cross-country in average terrain). The Mark II was the last Bolo with only two tread systems; all later marks were designed with "wide track" treads—that is, with multiple track systems across the full width of the vehicle to reduce ground pressure to the lowest possible value.
MARK III BOLO (2018):
A near contemporary of Mark II, the Mark III was actually designed as a "heavy" (300 metric tons) companion vehicle. The Mark III's single 150mm main gun (which was not turreted and had only a 20 degree traverse) was backed by an 8-gun infinite repeater battery, a heavy indirect fire support capability (four 155mm howitzers and a light VLS missile system), and an upgraded anti-missile armament. Unlike the Mark II, the Mark III carried only a single fossil-fueled power plant, strictly for backup use; power was normally drawn from heavy banks of ionic batteries, and the Mark III was the first Bolo designed from the outset to use solar film recharging. The vehicle also carried a marginally better sensor suite and a thicker durachrome hull (20 millimeter) which could be pierced at pointblank range (250 meters or less) by a 90 degree hit with the 140mm or 150mm DSFSLRP round; otherwise, it was effectively immune to anything short of a contact nuclear explosion. The Mark III was designed for a two-man crew with the second crewman serving as electronics officer (EW, sensors, etc.), but could be crewed by a single experienced operator in a pinch. The last Pre-Collapse Bolo, it was the first Bolo with multiple tread systems—inner and outer—with an independent power train for the inner pair, but maximum speed fell to 50 kph (road), 25 kph (cross-country).