There are 2 ways you can get through metel detectors on level 7 (traditions of the trade). 1 way is to pack any other sniper rifle, I.E. PGM, dragunov, Enforcer. NOT THE W2000!!!.
The 2nd way is to drop the case before passing through, then pick up the case on the other side. HAVE FUN!!

All levels - At the main menu,enter X, Y, B, LEFT, UP, RIGHT, L TRIGGER, R TRIGGER

All weapons and Skip level - During gameplay(not paused)enter R,L,UP,DOWN,X,A,click Left Analog Stick,press B,A,B,A.If you enter this code in the training area a message will come up saying that you have achieved Silent Assassin rank.

It will quit the training.Go back into the training area and you will now have all weapons.