I used the Madsen up until I unlocked the BAR. I had no intention using support for as long as I have but that BAR is too good to pass up.I managed to rank up enough last night to unlock it. Haven;t used it yet--will tonight--but stat wise the telescopic variant looks awesome with great accuracy & control.
I am currently using the Madsen MG Storm and it is pretty good too. It is basically a medium range assault rifle that works well on most maps..