OK, I took everyone's advise but I still died. So I thought, hmmm, let me use the magnum and the heavy machine gun I think its called the 249 since the magnum kilss with one shot and the 249 can be used for easier targets to kill faster. Well that worked. I stayed at the end of the tunnel, not going inside completely but only until other goons appeared and then retreating back and taking care of each one that appears while I was in the tunnel. It works. I killed off all the RPG guys and the shielded guys don't even get near me. What had to be done was that I get the magnum early in the game after using the shot to open that first door and shooting the guy in the back, there is a magnum on the boxes in the front room, never using any bullets but just collecting them until the end. I had about 50 bullets for the magnum, more than enough. Thanks for all your help!!
No problem, everyone has different ways of beating it I think....you just have to have the patience and persistance to do it, it's hard but it can be done....