In Armadillo go to the saloon. Go upstairs to the corner of the rail.

Shoot someone and let a witness go get the sheriff.

Now it gets fun - keep killing the deputies as they come in the door.

Watch the stairs, they always come to them, but never come up to the top. You can earn Bandito easily.

When your hurt just duck down then continue. If you look close you can kill sheriffs in the street or through the window.