Objective Individual Combat Weapon

Lore & Background

The OICW program was conceived to exploit advances in computer technology for a weapon that could fire grenades automatically pre-set to explode above or beside hidden targets. The central idea was a combination of a short assault rifle and a semi-automatic, low-velocity cannon firing airburst munitions. The winners of the first competition in the 1990s were ATK and Heckler & Koch, who built numerous prototypes of the XM29 OICW for the United States military in the late 1990s. These prototypes centered on a programmable 20 mm airburst munition-firing rifle, tested in various configurations: standalone, with a 5.56 mm weapon (based on the HK G36), or with an MP7 PDW. By the early 2000s, the design had settled into the XM29, based on the HK CAWS (Close Assault Weapon System). However, the weapon had serious problems: it did not meet weight or cost targets, and the 20 mm High Explosive Air Bursting (HEAB) munition was not lethal enough in testing. The kinetic-energy component had a 5.56×45mm NATO barrel only 250 mm (9.8 inches) long, too short to generate effective muzzle velocity for a standard infantry rifle. The weapon was also too heavy and too large for effective soldier operation. This resulted in the army starting development on new weapons, and finally shelving the XM29 in 2004. The OICW program was structured in three increments. Increment 1 was a competition for a whole weapon system family to potentially replace the M4 carbine, M16 rifle, M249 light machine gun, and some M9 pistols. This increment was put on an eight-week hold in July 2005 and was cancelled on October 31, 2005, with the stated reason being to reevaluate priorities for small caliber weapons and incorporate emerging requirements from Operation Enduring Freedom and Operation Iraqi Freedom. Increment 2 was the standalone XM25 airburst weapon using 25 mm munitions, intended as a special applications and support weapon. Increment 3 was the XM29 itself.

Reader's Guide

The OICW program's significance lies primarily in its role as a high-cost, high-concept failure that nonetheless produced several influential offshoot weapons and technologies. Although it did not achieve its goal of replacing the M16, the program cost millions of dollars and resulted in innovative weapon concepts. The kinetic-energy component evolved into the XM8 rifle program, and the airburst component developed into the XM25 airburst weapon. Other weapons stemming from or using OICW technology include the XM1018 (25×40mm HEAB ammunition), the M320 grenade launcher (originally developed for the XM8), the XM109 anti-materiel rifle, the XM307 ACSW automatic grenade launcher, the XM312 machine gun, the Mk 47 automatic grenade launcher capable of using smart 40 mm airburst grenades, and the Land Warrior system. The program also influenced the development of the XM26 Lightweight Shotgun System. The OICW's legacy is thus a family of specialized weapons and technologies that emerged from a single ambitious but ultimately unsuccessful attempt to create a revolutionary individual combat weapon.

Did You Know?

• The OICW Increment 1 competition was cancelled on October 31, 2005.
• The XM25 airburst weapon, an offshoot of OICW, uses 25 mm munitions.

The Airburst Revolution

The central ambition behind the OICW program was to solve a persistent problem in infantry combat: how to engage an enemy hiding behind a wall, a berm, or any other piece of cover that a straight-line bullet cannot reach. The solution envisioned was a programmable airburst munition—smaller than a traditional grenade but large enough to produce a lethal fragmentation pattern—fired from a low-velocity cannon integrated with a short assault rifle. Computer technology would allow the round to be preset to detonate at a specific distance above or beside the target, scattering shrapnel in a direction where conventional rifle fire was useless. This concept emerged in the late 1980s as a direct successor to the Advanced Combat Rifle program, inheriting its spirit of aggressive technological experimentation even as the ACR itself had failed to deliver a replacement for the M16. The OICW was never merely a new rifle; it was a bet that smart, pre-programmed explosives could reshape the geometry of close-quarters and urban fighting.

The Competition and the XM29

During the 1990s, the Army opened the OICW competition to multiple defense firms. Two principal contenders emerged: a design from AAI and its partner companies, and a joint effort led by ATK together with German firearms manufacturer Heckler & Koch. The ATK–H&K team won the contract and proceeded to build numerous prototypes for the U.S. military through the late 1990s. Their work explored several configurations: a 20 mm smart-grenade launcher paired side-by-side with a 5.56 mm rifle, the same launcher as a standalone unit, a pairing with the MP7 personal defense weapon, and an over-under arrangement that became the XM29 OICW. By the early 2000s the design had crystallized around the XM29 designation, built on the HK CAWS platform in a non-conventional 18.5×76 mm (12-gauge) caliber. The weapon was intended to combine a kinetic-energy rifle component with the airburst cannon in a single, soldier-carried system.

Why the XM29 Fell Short

Despite years of development, the XM29 ran into a cluster of problems that proved insurmountable. In testing, the 20 mm High Explosive Air Bursting round failed to demonstrate sufficient lethality, undermining the program's central selling point. The kinetic-energy component was constrained to be light and compact, forcing the 5.56×45 mm NATO barrel down to just 250 mm—roughly ten inches—far too short to generate the muzzle velocity needed for an effective standard infantry rifle. Compounding these issues, the finished weapon exceeded both its weight and cost targets, making it impractical for a single soldier to carry and operate in the field. By 2004 the Army had concluded that the integrated concept could not be salvaged and shelved the XM29. Rather than discarding the work entirely, the service split the program in two: the kinetic-energy rifle element became the basis for the XM8 program, while the airburst launcher evolved independently into the XM25, a standalone 25 mm smart-grenade weapon.

A Prolific Aftermath

Although the OICW never entered production as a single unified rifle, its technology seeded a remarkable family of follow-on programs. The Army formalized this through three increments. Increment 1 envisioned a full weapon-system family to replace the M4, M16, M249, and M9, with a modular shotgun (the XM26 Lightweight Shotgun System) as an accessory; however, after an eight-week hold in July 2005 to gather input from other services and to account for lessons from Operations Enduring Freedom and Iraqi Freedom, the program was cancelled on October 31, 2005. Increment 2 produced the XM25, a semi-automatic 25×40 mm airburst launcher that underwent limited combat testing in 2005. Increment 3 was the XM29 itself. Beyond these, OICW-derived technology fed into the M320 grenade launcher, the XM109 anti-materiel rifle, the XM307 and XM312 automatic smart-grenade launchers, the Mk 47 40 mm launcher, and the Land Warrior system. The program's failure, in other words, was also its greatest success: it generated a generation of innovative small-arms concepts.