In 1998 SW Swiss Ordnance Enterprise Corporation revealed that it had developed, as a private venture, a new 120 mm muzzle-loaded smoothbore mortar system called Bighorn.

According to SW Swiss Ordnance Enterprise Corporation, development of its 120 mm Bighorn mortar system was completed early in 1998 with about 600 mortar bombs, of various natures, being fired.

Although Bighorn has been developed as a private venture it is known that the Swiss Army has a requirement for a new 120 mm mortar system for installation on the locally designed and built MOWAG Piranha (8 x 8) armoured personnel carrier.

Bighorn can fire all standard and special 120 mm smoothbore mortar bombs including the Swedish Bofors Weapon Systems/Saab Dynamics Strix top attack terminally guided mortar bomb which is already in production for the Swiss Army for use with its twin 120 mm fortress mortar systems.

For rapid and accurate laying onto the target, Bighorn is fitted with a laser gyro-based navigation and positioning system which provides accurate position and weapon pointing autonomously during the fire mission. The weapon is rapidly laid onto the target using a control panel and joystick which is mounted on the right side of the mortar.

A semi-automatic loading system is fitted which enables a maximum rate of fire of four rounds in less than 20 seconds or six rounds per minute to be obtained. Maximum range depends on the type of mortar bomb and charge system used but is typically up to10 km. The barrel is 2 m long.

A special recoil system has been developed for Bighorn which is claimed to give recoil forces of only 30 per cent when compared to a standard 120 mm mortar system.

The Bighorn is turntable mounted and would normally be installed in a tracked (for instance United Defense M106) or wheeled (such as MOWAG Piranha 8x8) light armoured vehicle and fire through the open roof hatches.

Elevation and traverse is hydraulic with the hydraulic powerpack integrated on the actual weapon. There is also a power conditioner which makes the system independent from the vehicle's electric power supply. The design of the Bighorn is modular so that different user requirements can be incorporated without any redesign. Possible future options could include autolaying, adding a Global Position System (GPS) and onboard ballistic calculation.