I done this Attacking at Oasis in a helicopter. This is because if you have a gunner, you get points for assisting even though you didnt shoot at the target. You may get headshot, defense, saviour and avenger bonuses on top of the killing the enemy points reward. Also, if you have the American helicopter, you have rockets which means that if the Gold Cargo is in the open, you can claim points for damaging it. This can show up about 4 times before the 30 point bonus of destroying it so 70 easy points there. You should end up if it is a lengthy game with around 500 points which should be secure