This 76 mm rifled gun, designated the GT 4, was developed by LIW as the main armament of the Reumech OMC Rooikat (8 x 8) armoured car, first production examples of which were delivered to the South African Armoured Corps in 1989.

By mid-1999 it is estimated that over 180 of these vehicles had been built for the home market. So far there have been no export sales of this vehicle.

The 76 mm/62 calibre GT 4 gun retains the same chamber volume as the Italian Otobreda 76 mm Compact Naval Gun but fires different ammunition, developed in South Africa, in keeping with its role.

The 76 mm GT 4 gun was chosen for the Rooikat for a number of reasons including: the larger number of 76 mm rounds capable of being carried when compared with the 105 mm gun; the ease of handling ammunition moving across country; and the optimum selection of recoil forces and firing impulses for maximum crew operational effectiveness.

The 76 mm GT 4 gun has a vertical sliding semiautomatic breech mechanism and is fitted with a thermal sleeve and concentric glass fibre fume extractor. The recoil system consists of a concentric hydrospring with external replenisher, with maximum recoil being 370 mm.

The vertical sliding breech block is opened by means of a cam during run-up and the cartridge case ejected by means of two extractors. The cam can also be set to manual mode which prevents cartridge case ejection during run-up. This facilitates the sealing of the system during BC warfare.

A guardrail incorporating a cartridge deflector is mounted around the rear of the gun. The barrel has a bayonet type thread to facilitate fast assembly and is autofrettaged in the high pressure regions to allow for the use of high pressure ammunition.

The barrel has a constant pitch rifling and is equipped with a fume extractor. Provision is made for the possible installation of a muzzle reference system.

An auxiliary sight is mounted coaxially to the right of the gun and a range drum is fitted for use in the indirect mode, which is mounted on the guardrail.

Mounted on the left side of the gun is a 7.62 mm coaxial machine gun and the gun is also fitted with a loader's safety switch which is activated by a cam on the breech during recoil.

Two types of ammunition have been developed for use with this gun: HE-T and APFSDS-T, with the latter having an effective range of 2,000 m.

The 76 mm ammunition of the naval gun can also be fired by replacing the mechanical primer with an electric primer.

While the South African National Army uses the Rooikat with the 76 mm gun (GT 4), for the export market a version of the Rooikat armed with a 105 mm gun (GT 7) has been developed to the prototype stage. This is covered in a previous entry.

In production. In service with the South African National Army in the Rooikat (8 x 8) armoured car.