SlamDance, Inc. Hyper-Hammer

SlamDance, Inc. Hyper-Hammer is a close-combat weapon designed especially for full 'borgs. It is a heavy, solid-tungsten sledgehammer designed with ergonomic combat grips, spiked knuckle guards and a thumb switch-activated rocket booster built into the back of the hammer's head. When fired, the rockets blast the hammer around at near-supersonic speed, delivering unheard-of wound potential. Damage ignores soft armor and reduces it 2 levels, and hard armor only counts as 1/2 SP and is reduced 1D6+4 levels. The Hyper-Hammer may be used two times before needing to be refueled (with jet fuel). The handle and grips can be folded down, so that a large person could conceal the Hyper-Hammer under a trenchcoat-this is made easier by the use of a special shoulder rig, available from SlamDance, Inc. for 40eb.

Source

 * Solo of Fortune 2, pg.70,71
 * Blackhand's Street Weapons, pg.38