From their website:
The signature weapon of Cygnar’s Stormblades, the Storm Glaive is one of the best-known mechanikal weapons in all the Iron Kingdoms. Despite the short ranged electrical discharges that the weapon is capable of firing it is primarily a close combat weapon. This naturally leaves the Stormblades vulnerable to enemy gunfire as they advance to meet their foes in melee. Cygnar’s arcane mechaniks devised the Storm Thrower to both provide storm knights with covering fire and to enhance the accuracy of blasts produced by Storm Glaives.