Copper Mill - Multi-Level Building with Flammable Gas Leaks (Part 2)

Quickly take out the enemy throwing explosives at the top of the stairs, dodging out of the way if one of his projectiles lands nearby.

Just around the corner there are two wooden boxes where you can take cover and use a can or bottle to craft an improvised explosive.

The next 3 enemies come at you from the far right corner of the room. Shoot them as they approach. Or, if you want to be fancy about it, either toss a molotov at the gas leak on the far side of the room to create an explosion, throw a molotov or shrapnel grenade directly at the men, or shoot the hanging lantern as one of them passes underneath it.

If you throw a shrapnel grenade and it knocks an enemy down without killing him...

...provided there are no other enemies left nearby, you can run forward and finish him off with a melee attack: Press Y/F to attack...

...then tap X/E at the prompt to use the bow choke.

Continue around the corner and up the stairs, picking up more rifle and pistol ammo here and cloth on the next landing.