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W3900 Coil Gun

Developed in YE 39 for the U1 series of craft, the W3900 is a fast firing 80mm Coil gun designed to quickly fire a variety of projectiles.

W3900 on transport assembly
Maxiumum Rate of Fire 2000 RPM
Default Rate of Fire 360 RPM
Ammunition Type 80 mm
Length 6 Meters
Width 1.5 Meters
Length (gunpod) 8 meters


The W3900 is built on the lessons learned from the Casebreaker 80mm Cannon. While many weapons manufacturers were looking to build weapons that fire larger rounds, NAM, and specifically Heram J. Wazu was looking to do more with less. Fire smaller rounds, faster, with greater payload and in turn be able to store more of them. When a gun-pod was needed for the U1, the W3200 ended up being revisited. Though the ammunition size was kept, little else made it to the next iteration of the weapon.

As the W3900 was meant for aircraft, extensive effort was placed into increasing the fireing rate of the gun. A rapid-feed system is used to quickly dump ammunition from the ammo supply into the weapon itself, and precise computer control of the firing mechanism allows the gun to start accelerating a second projectile before the first shot has left the muzzle. This meant that the gun had to be of the coil-gun style, and would end up leveraging much of the technology that went into the Pack Power Armor to create the multiple, complex, electromagetic fields needed to launch multiple rounds.

Though the weapon can be mounted by itself, it is intended to be used with an aerodynamic gun pod and the built-in power, ammunition, and computer controls.

The weapon's launch systems are all computer-controlled, allowing for things like firing rate and muzzle velocity to be lowered as needed.


The W3900 mostly uses powerful electromagnetic fields to propell projectiles, so it can handle a variety of designes for ammunition so long as it is generally no wider than 80mm. The current ammunition that has been tested with the weapon includes what is listed below.

Sensor Fused Impact Projectile

This 80mm Round includes basic laser-communication gear, and the detection gear of a Wz-G3802 Small Optical Sensor sensor built into the nose of the round. This projectile has a tungsten core, and is designed to destroy its target by smashing into it at high speed. It can also provide real-time images from the area it is fired at up until it hits something.

Damage Tier 8, heavy Anti-Mecha
Range, Atmospheric1000 km

Smoke Screen Projectile

This 80mm Round includes a small rocket motor and very basic navigational systems that allow a destination to be set prior to launch and little else, the weapon doing its best to reach the intended target area before releasing a thick cloud of smoke to block line of sight. While the metallic smoke powder blocks visible light and radar it does not block thermal sensors.

Damage None, it's smoke
Range, Atmospheric1000 km


The full weapon system includes its own ammo store, computing, and power supply though these items can be removed and replaced with external sources.


The W3900 uses a cluster of Scale Datapads for computer control.


Power is provided by a pair of U-G3801 Hyperspace Tap Generator generators located on either side of the main launching apparatus.

Alternate Configurations

W3900 Arm Mounted Gunpod

The original W3900 gun pod carries 666 rounds in a large ammo drum situated behind the cannon. This massive gunpod has to be carried with both arm hard points in fighter mode, slung directly under the craft. In mecha mode the gunpod is situated under the right or left arm.

U1 with W3900 in arm-mounted Gunpod
Ammunition Capacity 666 Rounds
Maxiumum Rate of Fire 2000 RPM
Default Rate of Fire 360 RPM
Ammunition Type 80 mm
Power from host craft required

W3900 Minimized

The W3900 Minimized is a smaller gunpod that uses the ammo feed without the ammo drum. As such it can only hold 100 rounds of ammunition though the pod is small and light weight enough to fit on most hardpoints.

W3900 Minimized Configuration
Maxiumum Rate of Fire 2000 RPM
Default Rate of Fire 360 RPM
Ammunition Capacity 100 Rounds
Ammunition Type 80 mm
Length 4.5 Meters
Width 1 Meters
Length (gunpod) 5.5 meters
Power from host craft required
U1 with W3900 in minimized configuration Gunpod

W3900 Rifle Gunpod

The Rifle Gunpod pulls ammo from a W3904 Ammunition Pack. This gives the pod a total of 66 rounds, though the magazine can be ejected and replaced in combat fairly quickly. Like the other gunpods, the W3900 is encased inside of an aerodynamic shell that is hardened to withstand the rigors of space and atmospheric flight.

W3900 in Rifle Gunpod side view
Maxiumum Rate of Fire 2000 RPM
Default Rate of Fire 360 RPM
Ammunition Capacity 66 Rounds
Ammunition Type 80 mm
Width 1 Meters
Length (gunpod) 6 meters
Power from host craft required
Can be reloaded by replacing magazine in rear of pod
2 seconds to fully empty magazine on full auto
11 seconds to fully empty magazine on default fire rate
W3900 in Rifle Gunpod front view
faction/uso/u1-w3900.txt · Last modified: 2018/08/14 13:31 by