Well after battle number three over at the World At War community campaign, I have to slightly change my stance. Deploying a Vickers tripod on top of a church on a mountainside town allowed me to have a superior view and range of fire, and thanks to the long fog distance on the map it meant I could open fire on approaching vehicles and infantry quite effectively. Still wasn't super easy taking down infantrymen running around even as close as 100m, but I will concede it was pretty damned useful.
Of course in the same game there was an enemy open topped anti-air vehicle far away almost at the fog line, I had a rifle and lined up a shot at where I thought the gunner would be sitting and indeed sniped a man off of a gun from 300m away with a basic rifle. So stationary targets manning guns are still damned easy to kill with a rifle.