On the casino mission at the end you will be asked by goldfinger to protect the omen weapon .

You will be shut in an circular room with no doors and very few weapons there are windows going around the room, and thats where the enimies will attack.

They will start with light armed men then will go on until the semi-boss (the ones with the shields that you faught in the rooms around the vault) there is enough room under neath a wondow to cruoch and guard the outher windows.

The most important things are to stay crouching and never guard one window at a time for this will end in death.

There is only one gun that is able to keep the room clear and that is the heavy two handed machine gun that you can find in the outer rooms of the vault.

IF YOU TAKE A PANSY WEAPON IN YOU WILL GET KILLED so dont there are a couple of meg rails in there but only use them if you run out of ammo.

HAPPY HUNTING.