When you get to the woods, there will be a house on fire. Go up to the window to the left of the house, and it will have broken glass. Jump, crouch and walk into it. You can shoot through the windows and walk around. If you jump on a window not broken from inside, and jump towards the ceiling, you can see part of the top.

Any level you're on when you're in the middle of reloading your weapon you drop it there for about 5 seconds then pick it up & you should have lost no bullets

to get unlimied ammo, enter "2ndsquad" as a profile name

Go to the select chapter screen. Hold L1 + R1 then press Up(2), Down(2), Lef(2),
Right(2), Square, Right, Square, Right, Square.

This was already posted, but their's was wrong.

To unlock all levels:

Hold Down L1 AND R1 the whole time while pressing the buttons!

Up, up, down, down, left, left, right, right, square, right, square, right, square, right.

Enjoy your gaming!!!

Enter this code in the chapter select menu tounlock all levels hold R1 and R1 and then press UP-UP-DOWN-DOWN-LEFT-LEFT-RIGHT-RIGHT-SQUARE-RIGHT-SQUARE-RIGHT-SQUARE

HAVE FUN CHEATING

Unlock All Levels-At the chapter select menu hold L1 + R1 and press UP, UP, DOWN, DOWN, LEFT, LEFT, RIGHT, RIGHT, SQUARE, RIGHT, SQUARE, RIGHT, SQUARE
Infinite Ammo-Go to the options menu and press R1, R2, SQAURE, L2, CIRCLE, R1, TRIANGLE

Choose "Single Player" from the main menu and select the "Chapter Select" option. When the chapter selection menu appears, hold L1 + R1 and press UP, UP, DOWN, DOWN, LEFT, LEFT, RIGHT, RIGHT, SQUARE, RIGHT,SQUARE to unlock all of the chapters.

Keep moving forward to cover when you are not under fire.

At the chapter selection screen, hold L1 + R1 and press Up(2), Down(2), Left(2), Right(2), Square, Right, Square, Right, Square to unlock all levels.