XKH-71 Panther rifle

The XKH-71, also known as Panther, system is an incredibly versatile weapons system. designed to provide complete domination in a battlefield situation.
The gun is simple in its design. It consists of a very long barrel, surprisingly made of frictionless ceramic rather than the conventional metal. Instead of a firing pin, an extremely powerful laser is located at the end of the barrel. This laser has the job of creating a plasma from the ammunition. a very powerful electron gun (a more powerful version of the cathode in a TV) is also located at the rear of the weapon, and allow the charges to be ionised if needed. The barrel is itself surrounded for its entire length by a large gold coil, which is protected by the casing. This gold coil allows the weapon to create a very strong electromagnetic field inside the barrel, which is what accelerates the ionised projectile.
None of this would be possible without the support of a very efficient powercell, which is located over the stock of the weapon.
The ammo itself is incredibly simple. In the 40 round magazine, there are 40 metal slugs. These slugs have no propellent, and are usually made of solid copper. most malleable metals will do, and there have been successful trials with iron, aluminium, lead, steel, magnesium, nickel zinc, gold and silver. In one particular case, the laser was overpowered and the slugs were even made of iridium. These slugs look like 70mm(~2.75in) long cylinders of metals, with a diameter of 18mm(~0.7in). Since they are so trivial to manufacture, they can even be smelted in the field using a small clay furnace and available metal ore.
The gun fires by vaporising the metal slug using the laser. depending on the laser's firing time and intensity, the projectile can either be:

1. Partially vaporise, which creates the same effect as a normal chemical weapon as the hot plasma expands behind the rest of the slug. This is achieved with a very intense but short pulse.
2. Molten, in which case it will then be ionised by the electron gun and accelerated by the barrel
3. Completely vaporised, in which case the entire slug is transformed into a dense metal plasma, and can be accelerated at will.

Also notable is the weapon's Muzzle. When firing ionised projectiles (molten or plasma) the muzzle is electro-magnetic, and the fluid can be forced into a wide variety of configuration.

The rifle is designed in a bullpup configuration, to maximise barrel length. (bullpup: magazine behind the grip) They are remarkably bulky in their design, with a blocky appearance. Remarkably, they have only one internal moving part besides the trigger (which incorporates the safety mechanism.). The slug loader is mounted on a quick response solenoid. This is in fact the bottleneck which reduces the rate of fire to about 420 rounds per minutes. This low rate of fire is a constant point of discontent amongst Liberty operative, and has forced a spirit of precision marksmanship amongst the Panther users.
The rest of the rifle is encased in a poured lightweight resin, protecting all the elements from the environment, and effectively allowing the system to work in difficult condition, such as underwater (plasma causes supercavitation, which allows a reasonable underwater effectiveness.)
The optics are streamlined with the weapon, and are mostly electronic, although a combat sight is attached. They integrate fully with the Liberty infantry data system, effectively allowing the warrior to have sighting information on his head-up display. This effectively allows the Guardians to fire their rifle without line of sight.
From a standard human point of view, the rifle is very long, nearing 1.25m (nearing 50in) and would be classed as a general purpose machine gun for its size. (it must be remembered that Guardians are genengineered)
(For an idea of the look and feel, the Panther looks like a bulkier and longer FN F2000)

It must be noted that this is by now means a definitive list, since the weapon's many variables can be changed to give rise to a wide variety of uses. But it is a list of the most common configuration. The soldier's individual preferences can be programmed into the thumbwheel fire selector, from 1 to 5. The finer variable adjustments are carried out through the HUD software. 'P' designates plasma rounds, 'M' molten or metallic, while 'S' slugs, which are only partially consumed. All projectiles other than the 'S' also cause severe ionising damage if in contact with skin or clothing. This effectively means tissue necrosis around the point of impact.

This projectile is created by constricting the muzzle magnetically when firing a full-plasma projectile. This creates a long, thin needle shaped projection. It has excellent range, and will penetrate through most metallic armour simply by melting it. The projectile itself burns brightly, and will often set fire to flammable material it comes into contact with. against reactive armour, this fares well, since by the time the armour has fully reacted, the projectile has still not fully made contact. (the needle is ~1m long) Against ceramic armour, this lacks the kinetic energy to break it, but the splash damage will often be sufficient to disable the target.

By reversing the polarity of the magnetic muzzle, the Plasma can be dispersed widely when it leaves the barrel. This creates a travelling and spreading plume of plasma, which will penetrate most metallic armours, but is incredibly efficient against unarmoured or woven protection. The plume reaches the size of a basketball at approximately 150m, and looses its effectiveness soon after that. It retains the brightness of the 'P' needle projectile.

This configuration resembles the firehound, but with molten metal. Since the metal has far greater coherence in flight than the plasma, the effective range is far greater, retaining full effectiveness at 450m. The kinetic energy is considerable, and can be approximated to being hit by a very large sledgehammer. Even if well protected by a ceramic armour, Immediate 3rd degree burns are often caused by the dispersion of the molten material.

The 'Slug' or solid round is created by giving a very intense but very short blast on the laser. This vaporises the rear of the round, which creates an expanding cloud of plasma behind the remaining slug. To keep this plasma at an adequate temperature, two further laser blasts occur at 1/3 and 1/2 of the barrel length to keep the plasma expanding.. The projectile itself, will be softened by the effect of the plasma, which will help it achieve a slightly aerodynamic shape during flight. Since this is effectively copper, it has some chance of fragmentation upon impact. This is however not the preferred use, since the effective range is very short. Surprisingly, the report is not very loud, comparable to modern weaponry.

This special use is the same as the 'M' blast. The difference is that the laser fires again when the projectile is near the muzzle, so that the liquid metal is heated to its point of spontaneous combustion, and immediately begins to oxidise in the air, burning at extremely high temperatures (not quite the plasma range). This allows the defeat of even the thickest metal armour, and will usually set fire to most substances.
In an some situations, the laser itself can be used without any projectile, creating an invisible attack on the target. Atmospheric effects, however, can cause this to be temperamental at long ranges, although at short or medium range, it is devastating. This is commonly used to defeat all types of personal armour in close quarter combat, as well as armour penetration when within close range. In silent or stealth situations, the invisible nature of the laser (the pulses is in the nanoseconds), as well as the lack of sound makes it a very effective tool.

Type: assault rifle
Mechanism: Liquid metal/plasma gaussian acceleration
Effective firing range: 1700m (the plasma automatically shapes itself to a teardrop shape from air resistance) the range of a solid or molten slug is considerably less. The muzzle velocity can also be very high.
Overall length: 1256mm (49.4in)
Barrel length: 924mm (36.4in)
Weight: 21.45kg(loaded) 15.10kg(dry)
Round: 18mmx70mm LIB
operational powercell life: ~4200 shots