Really enjoying the Scar-h at the moment. It really hits hard as long as you are accurate. Takes about 3 hits to take down an un-injured person. I'm using it in semi auto mode.
I've been rocking the Scar-H today: http://battlelog.battlefield.com/bf4/battlereport/show/1/742725203327379072/917377806/
HD-33, laser, heavy barrel, ergo - kicks like a mule but those first few rounds go where you are pointing heh.