XM29 OICW

The OICW is a weapon cut from Half-Life 2. It can be found in the playable Half-Life 2 Beta. It was to be used by the Conscripts and the Overwatch Soldiers.

The XM-29 OICW (part of the U.S. Army's Objective Individual Combat Weapon program) was an assault rifle concept that sought to combine a standard 5.56mm assault rifle (what would later become the XM8 prototype rifle) with a 20mm cannon and complicated computerized sighting system. A number of problems, including weight, bulk, lack of effectiveness of the 20mm airburst round, and ultimately cost of single unit exceeding 10 000 USD have led to the project effectively being shelved.

The XM-29 never entered full scale production or served with any military, but that hasn't stopped a number of games and films from depicting it in the hands of soldiers and mercenaries, including Half-Life 2 in its Beta phase. In the game, it was originally planned to be the Combine Overwatch and Conscripts' weapon of choice, but it was later replaced by the fictional Overwatch Standard Issue Pulse Rifle (OSIPR).

In the leak, the player can only fire the rifle portion of the gun and zoom in. The grenade launcher was shown working in promo videos, but it doesn't in the leak (the grenade launcher function is in the code, but is disabled). It appears that it's grenade function was moved to the SMG1 by the time the leak was made, as getting close to the SMG grenades in the map "zoo_item" causes the message "AR2 Grenades" to appear on the screen.

The OICW has good accuracy as long as the player fires in short bursts, and the scope turns it into a decent makeshift sniper rifle.

Trivia

 * Interestingly, the scope on the OICW when unzoomed is broken in-game; it shows a solid light green instead of the scope texture. However, when looking at the model in the HLMV model viewer, the scope has its proper texture.