Act 4: C5 - The Best-Laid Plans

Go up and save the ammo for after. Go to the doorway and it closes and you are ambushed from above. Try to kill them before all your cover is gone, then focuse on the ones to the other side. Now pick up the ammo and now the gates back a bit will lead you to the alternate path; and we will go down the left one facing the palace, though I'm sure either would work. You will engage a few enemies and a bloodmount along the way. When you get to the back and fight a Kantus, after the battle go to the right of the lift and look on the second steps along the wall for by far the most paper that goes the farthest off-topic in the game.

Get on the lift and take it down to the bloodmount holding area. Some frags on the right side, then go pull the lever for a choice; choose left, the upper path. Go up and look out of any of the openings on the right and assist your decoys down below as they fight the good mix of enemies below, and a grinder up high. Follow the path to a room with a switch on the ground and step on it. There is ammo where the battle was and two outside in an open area. Your team gathers atop some stairs you would go down, but instead take the stairs behind them and find an artifact at the end by some ammo. Come back and head down the stairs.

I say just run down the steps and slice up the enemies you see with your chainsaw, much easier than a shootout. There are two guards, then three guards and four tickers, then one, and the rest is just pairs of guards at a time; so mix in chainsaw slices with bullets and you shouldn't have much trouble. At the big room will be guards scattered around, and then some tickers. Grab ammo before the scene hits.