Modern infantry-level mortars come in several major standardized caliber forms - 60mm, 81mm, and 120mm. While all are functionally similar in offering indirect fire support, each plays a slightly different role on the battlefield. Lightweight types, such as the 60mm, are designed to be highly-portable, quick to deploy, and easy to operate and such weapons can outfit specialist troops like paratroopers. For the South African Army, this role is fulfilled by the M4 "Commando", a 60mm system built upon the stated attributes, providing squads with indirect firepower at short ranges against stubborn enemy forces. Due to its handy operation, it serves both airborne troopers and special forces operators.
The Commando series is manufactured by Denel Land Systems of South Africa.
The M4 can fire various "flavors" of projectiles such as High-Explosive (HE), illumination, smoke, and practice rounds out to ranges of 2,100 meters. A breech-based trigger operated by a lanyard replaces the traditional firing pin action common to most mortars and this allows the trooper to carry the weapon loaded and ready-to-fire. The Commando also lacks a bipod assembly and is set on the ground by its baseplate and leveled by hand. A sighting device and range table help the operator figure range to the target and the flight path of the exiting projectile. The launch tube measures 650mm long and muzzle velocity of the outgoing shell is 171 meters per second. Minimum engagement range is 100 meters.
A standard operating crew numbers two.
Beyond the South Africa Army, the army of Colombia is a known operator of the Commando. The M6 fulfills the more traditional 60mm mortar role and the M3 is the 81mm version for the South African Army while the M5 is the 120mm model.