The XM29 OICW (Objective Individual Combat Weapon) was a series of prototypes of a new type of assault rifle that fired 20 mm HE airbursting projectiles.

Developed by Alliant Techsystems, with Heckler & Koch as a major subcontractor, the most commonly seen version of the XM29 consisted of a semi-automatic 20×28mm smart grenade launcher, an underslung "KE" assault carbine (derived from the HK G36 then in its late developmental stage) firing a standard 5.56×45mm NATO round, and a top-mounted computer-assisted sighting system with integrated laser rangefinder, thermal vision night vision capabilities, and up to 6× optical telescopic sight.

On the other, while its caliber and velocity is more similar to light cannon, it does share traits with other infantry grenade launchers.

The OICW Increment One Request for Proposals was cancelled in October 2005, while development of the 25×40mm XM25 continued, and the 25×59mm OCSW program as well until its termination.

It is not clear if LSAT is intended to meet the goals of OICW Increment One or if it is a standalone weapon system.