When you first arrive on the Bar Level you find a Duty Post that denies you access (because of their war with Freedom) until you become their friend. If you've tried sneaking in you know they shoot you no matter what. If you've run down to the Freedom Camp and picked up the free Vintar rifle, you can still get into the Duty Camp to get ammo for the Vintar.

To the right of the Duty Camp gate is a climbable tower. Climb to the top and jump onto the nearby roof. Run in the direction directly away (180 degrees) from the Duty Guards. At the edge, jump between two smokestacks to the lower-level roof directly opposite. From there drop to the ground. Notice you jumped over a mass of jumbled pipes and such. Look around first before moving. You'll see a room with a Duty Officer standing in it, alone. Go in and talk to him. He also will buy anything you bring him, and seems to have an unlimited amount (over continuous visits) of ammo. Do his mission if you like, but it's very difficult.

When you're ready to leave, don't go out through the front gate. You'll just get shot. Instead, go over and look at the jumble of pipes and ducts. You can jump up onto them and by careful manipulation of the jump / crouch / low crouch / move forward keys you can snake your way over an obstructing pipe and get out. With skill and practise you can be in and out in mere minutes.

Having lots of Vintar ammo makes life substantially easier in the game. This works in the upgraded version of the game too.

Submitted by Frank Keough