Medal of Honor: Rising Sun Tips

Sten Mk II in Supercarrier Sabotage
After you get captured, there will be a cutscene. When the cutscene is over, kill the two guys that come into the room with the T-99 that Bromley threw to you. Once they are dead, walk up to the table with the Sten Mk II on it and you will pick it up. Now you can switch between them.