Alliant Techsystems / Heckler-Koch XM-29 SABR / OICW assault rifle (USA)

the left side view on the XM-29 OICW, showing its controls on the sighting unit

the major components of the XM-29

XM-29 OICW ammunition - HE (High Explosive) ant TP (target practice) rounds for 20mm unit and KE (Kinetic Energy) 5.56mm NATO round

Caliber: 5.56 mm NATO (KE) and 20x85mm (HE)
Action: Gas operated, rotating bolt (KE), unknown (HE)
Overall length: 890 mm
Barrel length: 250 mm (KE) 460 mm (HE)
Weight: ca 5.5 kg empty; ca 6.8 kg loaded
Magazine capacity: 20 or 30 rounds box (KE) and 6 rounds box (HE)

The history of the one of the most ambitious projects in the history of small arms, known as the OICW, or the Objective Individual Combat Weapon, began late in the 1986, when the US Army Infantry School at Ft. Benning published a military paper, named "Small Arms System 2000" (SAS-2000). Despite the current trends towards the caseless and fleschette ammunition and appropriate weapons, researched and developed under the ACR program (see HK G11 and Steyr ACR entries for some details), this paper stated that the conventional small arms already reached its technological peak, and the only way to increase the hit probability in the small arms is to introduce a weapon that will fire explosive and fragmentation warheads, combined with the smart fusing and sighting / aiming technologies. While the most small arms research during the late 1980s in the USA was conducted under the ACR program, the idea first developed in the SAS-2000 was supported by another US military paper, published in 1989 by the US Army TRADOC (Training & Doctrine) center. This paper, called "The Small Arms Master Plan" (SAMP), requested for a family of infantry "Objective" weapons, namely the Objective Individual Combat Weapon (OICW), Objective Personal Defense Weapon (OPDW), and the Objective Crew Served Weapon (OCSW). The SAMP stated that such weapons must utilize the latest developments in computers and visual technologies, as well as in the small arms, and combine both high explosive warheads and traditional bullets fire capabilities in a single weapon, that should be fielded circa 2000. Of cause, the timelines and most of the weight and cost requirements set in this paper looked unrealistic from the start, but the development of the Objective weapons began in the early 1990s.