I asssume you mean the part entering the airport where you're riding the luggage conveyor then ascend to the catwalks above? That was the hardest part in the game for me on Hard. I improvised and got off the conveyor just before the little tunnel part of it and stood to the left of that in cover. It kept me away from fire and let me save some ammo and health. I wound up with lots of auto 9mm ammo and didn't have to use the laser sight rifles as much.
Yeah the laser sights are strange. Even when you get all golden gun upgrades for some reason any laser sight equipped weapon has tons of recoil. Only thing you can do is aim mid torso just above their armored vests and fire in bursts. If any come to rush you blind fire with the auto 9mm if you have the ammo for it, but that's only necessary on Hard or higher. Another strange thing is ammo in that spot is hit and miss. Sometimes you get a lot, sometimes very little.