A hammercannon is a weapon archetype that appears in multiple forms, but is usually a powerful kinetic weapon with a heavy axe head built into the front, similar in concept to a bayonet. It’s commonly used by the Madroneans and the Korrvain, and sometimes by other races that favour physical strength, such as the Cho'zhar, Inorr and Yu Ghreda.
The blade of the axe runs parallel to the length of the weapon, thus it’s swung like a traditional axe. It’s considered an essential part of the weapon rather than a mere back-up, so the gun component is built extra robustly, to handle repeated swings without being damaged. Compared to a traditional bayonet, the axe head is very heavy, thus far more effective against armour, but it makes aiming difficult for those not strong enough to wield it properly. Most hammercannons are either shotguns or high-calibre assault rifles.
The name hammercannon is a vestigial term. It’s thought that the original designs incorporated a hammer instead of an axe, and that the name stuck around even after they were mostly replaced by axes. A few uncommon designs still use hammers, though this is rarely as effective. Some people refer to hammercannons as axecannons, but the name never caught on with the masses.