M203

The iconic US under-barrel 40mm grenade launcher — a single-shot, slide-forward break-action launcher that equips M16 and M4 rifles with high-explosive, HEDP and specialty rounds, and the standard squad-level grenade system for more than three decades.

Overview

The M203 is a single-shot, manual reloading under-barrel grenade launcher that attaches to the M16 and M4 families of assault rifles. It fires the NATO-standard 40×46mm low-velocity grenade using the high-low pressure principle, giving an infantry squad organic, close-range indirect-fire and light anti-armor capability without removing the rifle from the fight. Adopted in 1969, it replaced the standalone M79 “Thumper” and the problematic XM148, and remained the US standard until the fielding of the M320 starting in 2009. Despite its legacy status, the M203 remains in widespread service with US forces and dozens of allied nations.

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