Successfully complete the game. Start a new game session to find the following weapons at the indicated locations during the listed mission.

Arc Charger: In "No Way Out" search the end of the hallway near the officer's quarters.
Backlash Grenade: In "Cathedral," search the first room on the left inside the house.
L11-2 Dragon: During "Evacuation," search the small bunker at the end of the Radial Mine path.
Reapers: During the "Gauntlet," search the house in front of the square.
Splitter: During "A Desperate Gamble," search the second floor of the mall next to the vending machines near the windows.