APK MOD INFO
Name of Game: SHADOWGUN
VERSION: 1.6.3

Name of the cheat, mod, or hack (credits: wendgames):
-UNLIMITED AMMO

SHADOWGUN MOD APK 1.6.3 (Unlimited Ammo)

Download the CACHE file/OBB file. They should be .zip or .rar files.
Extract the file to your sdcard.
Move the extracted folder to the location: /sdcard/Android/obb