A Pulse Pistol is an advanced Tau Pulse Weapon that utilises pulsed induction fields to propel lethal micro-bursts of plasma over short ranges. A Pulse Pistol is a far smaller version of the Tau Pulse Rifle, and has a damage output that outclasses the standard pistol weapons of every race the Tau have yet encountered. As a pistol-sized Pulse Weapon, it is only used by certain Tau personnel as a basic defence and hold-out weapon for use in desperate situations. Pulse Pistols are most commonly issued to Sniper Drone Team Firesight Marksmen, although Tau Commanders who utilise a Tau Battlesuit Ejection System are also issued Pulse Pistols to aid them in making their way to safety if their Battlesuit has been destroyed. Tau Air Caste pilots have also sometimes been known to be armed with a Pulse Pistol to help them make a getaway from their Escape Pod, whilst Escort Drones are armed with twin Pulse Pistols to help protect their Water Caste master if necessary.
Pulse Pistols were first developed during the Tau Empire’s Campaign of Cleansing from 606.M38 to 792.M38, the first prolonged war 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 the first Pulse Weapons. As a result of this campaign, the Dal'yth Sept was successfully founded.
The Pulse Weapon is a small weapon, but 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 comprise a solenoid. When current is passed through them, these coils generate an electromagnetic field oriented along the barrel. At the front of the pistol are the weapon's two muzzles, just behind which is a circular apparatus similar in appearance to a bolt-head, that serves as a recoil stabiliser. Behind 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 16 shots before it needs to be replaced. A remote thermal sight adorns most models of Pulse Pistol, atop and slightly forward of the trigger assembly, which combines with the weapon's advanced stabilisers and recoil reduction to make it highly accurate during aimed fire.
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".
- Codex: Tau (3rd Edition), pg. 19
- Codex: Tau Empire (4th Edition), pp. 26, 29, 40
- Codex: Tau Empire (6th Edition), pp. 28, 46, 66-67
- Imperial Armour Volume Three - The Taros Campaign, pp. 80-81
- Rogue Trader: Into the Storm (RPG), pg. 121
- Deathwatch: Core Rulebook (RPG), pg. 366