The battle_rifle.gun.base002.obj file you have requested: Models / Battle Rifle Gun - 215.07kb is not available. Perhaps try browsing all files for the game Halo 2 and upload any files you want to share or are missing. This is the only information we could locate:
It's a modified version of the battle rifle but with a drum magazine, grenade launcher and scope. An assault rifle model with grenade launcher, for milkshape.