Call of Duty 2 No Hud

Hide/Show Hud

1. Enable console from the in-game options. 
2. Press the Tilde "(~)" to open the console.
3. Type seta thereisacow 1337 and press Enter.
4. In-game type this to toggle hud on/off:

cg_draw2D 0
cg_draw2D 1

Useful commands

cg_drawcrosshair 0/1   //toggles crosshair on/off
cg_drawgun 0/1   //removes weapon (may not work)
cg_fov <>   //changes the FoV (values must range between 60 and 160)

Source

• Call of Duty Developer console ; on Call of Duty wikia

Screenshot

Call of Duty 2 No Hud