The XM29 OICW is the effective predecessor to the OSPIR. It is still in use in the leak, and thus fully present.
The OICW, standing for Objective Individual Combat Weapon, is the direct predecessor to the later OSIPR. It is a powerful assault rifle with the ability to zoom in on enemies. It it used primarily by Combine Soldiers. Rebels are never seen using it.
Similarly to the OSIPR, it is a powerful mid-range weapon when used in short bursts of 3-6 shots. Going beyond that tends to cause the OICW to quickly gain severe recoil and become much less accurate.
Unlike the OSIPR, however, it is a useful weapon at long ranges, due to the scope. When firing at enemies from the scope, your shots are perfectly accurate, however the fire rate is much slower than when not zoomed.
Another difference from the OSPIR is that the number of clips the player can carry in reserve is numbered at five, rather than two. Thus, it can be used more heavily without a serious risk of running out of ammo.
Cut Grenade Launching Function
While in the playable Half-Life 2 Leak there is a zoom function as the secondary attack of the OICW, it seems that early in development the weapon instead possessed a grenade launcher as it's secondary attack:
- In the leaked E3 2002 trailer, the player can be seen firing a grenade at the strider with an OICW;
- The SMG grenades are still named "AR2_grenade"s internally;
- In the WC mappack map zoo_item, going to the SMG grenades causes the message "AR2 Grenades" to appear on the screen.
In both the leaked and the retail codebases, there are also snippets of code that allow the Combine Soldiers to use this secondary attack, in a manner similar to the HECU Soldiers in Half-Life 1. These code snippets are commented however, suggesting that this ability was cut very early in the development of Half-Life 2, possibly due to gameplay balancing problems.
Alongside everything else leaked, the OICW had the official source files for its viewmodel and a reference image for it leaked.
In the source files of the OICW, there is a version of the model present that has had the scope (poorly) removed. This version matches up with an unused HUD icon of it (in halflife2.ttf) without a scope, and it appears to show that the zooming function on the OICW was cut before the OICW itself was. Considering the incomplete state of the scope removal, however, there may not have been much of a gap between the two removals.
Besides the scopeless version, the source files are largely mundane.
One of PelPix's leaks was the reference photo for the OICW, from which several textures for it are adapted from. Additionally, searching "OICW" brings up the original version of that reference image. It is interesting to note that this particular variant of the OICW was made in January of 1998.
Alongside the current textures in the Leak are two others from an earlier version of the model. They appear in a few early screenshots of Half-Life 2.
Curiously, the old scope texture is still in use on the worldmodel.