A Pulse Rifle is the main infantry weapon of the Tau Fire Caste, a Pulse Weapon that utilises pulsed induction fields to propel lethal micro-bursts of plasma over long ranges. A Pulse Rifle is the standard-issue weapon for Fire Warriors, and has a range and damage output that outclasses the standard weapons of every intelligent race the Tau have yet encountered.
Pulse Rifles were developed during the Tau Empire's Campaign of Cleansing from 606.M38 to 792.M38, the first prolonged conflict of the Tau against the Orks. Whilst the Tau suffered many defeats early on, they were ultimately able to eradicate the Greenskins, thanks in part to the Earth Caste refinement of Pulse weaponry. This campaign led to the founding of the Dal'yth Sept.
The standard-issue Pulse Rifle is a very long weapon, with a length many times its width and height. The bulk of the barrel is surrounded by coils of conductive material, visible in some patterns along the top of the weapon, which produce a solenoid. When current is passed through them, these coils generate an electromagnetic field oriented along the barrel.
At the front of the weapon are the weapon's two muzzles, just behind which is a circular apparatus that looks like a large bolt head that serves as a recoil stabiliser. To the rear of the barrel mechanism is the primary magazine, and behind that the trigger assembly and stock. Within the stock is the secondary magazine, or power cell, which is able to provide up to 36 shots before it needs to be replaced. A remote thermal sight adorns most models of the Pulse Rifle, atop and slightly forward of the trigger assembly. The thermal sight, combined with the weapon's advanced stabilisers and recoil reduction make the Pulse Rifle extremely accurate and deadly.
The Pulse Rifle works by electromagnetically accelerating a plasma shell down its barrel. In effect, it is a miniature mass accelerator. On firing, a ferromagnetic, solid slug is chambered from the magazine and turned into plasma by electromagnetic induction, as it would be relatively easy to alternate the coil current at frequencies sufficient enough to heat the coil to an extreme temperature while keeping it in the chamber. The solenoid is then charged fully, propelling the newly produced plasma out of the gun at an extreme velocity while keeping it cohesive.
Though this electromagnetic field continues to keep the plasma together until impact, residual plasma is expelled from the barrel to produce the weapon's considerable muzzle flash. Maintenance of the field is also aided by a bolt-like apparatus, which increases the field strength and therefore the range. The weight of the bolt also serves to dampen the recoil from firing. Without the electromagnetic field, the fired plasma would all dissipate at the barrel mouth, producing a weapon with a range of approximately twenty centimetres. As it is, residual energy and waste plasma, together with the heat produced by energizing the coil, necessitates two barrels to avoid overheating.
The power required to generate these immense electromagnetic fields comes from the secondary magazine which is effectively a very powerful and dense rechargeable battery in the weapon's stock. It is changed less frequently than the primary power pack, and can be recharged from the firer's suit or combat armour. Vehicle-mounted Pulse Weapons are usually connected directly to a suitable power source, allowing higher rates of fire with sufficient heat dispersal and eliminating the secondary magazine.
Pulse Weapon rounds do a great deal of damage on impact, mostly due to the extreme thermal energy of the plasma mass and the speed with which the projectile impacts, which helps ensure that armoured targets are more heavily damaged. The electromagnetic field that holds the charge together flattens on impact slightly before breaking, which causes the resulting impact to spread over a wider area than would otherwise be possible. The speed at which the plasma projectile is launched is so extreme, that in some cases, it has been known to "light the air on fire".
Compared to other infantry weapons, the Pulse Rifle trades rate of fire for damage. When compared to a Space Marine Bolter, it fires at a far slower rate but does significantly more damage and possesses a greater effective range. Pulse Rifles also have significant recoil, which requires that the user be stationary to fire most effectively. This, combined with the Pulse Rifle's long range, means that Tau troops are best served by staying more or less stationary. Pulse Rifles still retain most of their effectiveness on the move nonetheless, and can be utterly devastating weapons when used correctly.
- Codex: Tau (3rd Edition), pg. 19
- Codex: Tau Empire (4th Edition), pg. 29
- Codex: Tau Empire (4th Edition), pp. 28, 36-37, 66-67
- Imperial Armour Volume Three - The Taros Campaign, pp. 80-81, 178
- Rogue Trader: Into the Storm (RPG), pg. 121
- Deathwatch: Core Rulebook (RPG), pg. 366
- Games Workshop Website - Kroot Shaper