[MetalMilitia]

I think one of your main problems is that you're not shouting at your team enough through a microphone. It's impossible to get a good game going without communication.

As for the barn I've always found it more difficult to defend than the top floor of the house. If two players go in the room directly in front of the stairs and watch the windows, one person stays in the doorway watching the other doors on the landing and one player shoots anything that comes up the stairs you can hold out quite easily till the tank turns up.

Once that happens you need to get downstairs/outside until he's dead then get back to the original positions.