go to this site.
http://forums.socom.com/t5/SOCOM-U-S-Navy-SEALs-Fireteam/Here-is-how-to-get-the-F2K-and-the-TAR21-w-out-hacks/td-p/643971here are the steps from the site. this unlocks a couple guns.
~if you have a pspgo this will not work for you (if you downloaded the game it wont work for you, must have a UMD for it to work)!!!
~u need a computer and a USB cord (this works for windows and mac)
~u need to remember your log in email and pw
~use the psp that you play ftb3 on
~log out of your psn name because your going to create a new one
(just go to account management and hit the triangle button, it should say "Delete account" say yes)
-make a HONGKONG playstationNetwork name
-enter the playstationStore on the HONGKONG NAME
-enter the search by clicking the magnifing glass. enter in "fireteam bravo 3"
-now a list of ftb3 add-ons will pop up.
-download all the add-ons! (if you have the f2k already, still download it anyways!)
-once you are done download every single add-on plug your usb into your computer and into the psp
-go into usb mode
-click your psp folder and inside your PSP folder there will be a GAME folder
-under GAME you will have a folder that starts with the letters NPH rename it to UCUS98716
(if your from the UK rename your folder UCES01242)
-now save it log out and return back to account management
-press triangle , delete the account, then log back into your american acccount
-you should have all add-ons and characters