27/3 is my record that I can remember lately. And that was me playing Insurgency using the SAW as GASP, a light support weapon as opposed to a run-n-gun spray-and-pray longer-magazine M4 like most people tend to.
In other words, I found a good choke point, dropped the bipod and just laid into anyone that happened to have the misfortune of not wearing desert camo and wandering into my sights. It helped that my team wasn't retarded and was doing a good job of making sure I didn't have to worry about being flanked, and every once in awhile I'd move to a different position, allowing someone else to take the spot I'd been holding so I could shore up defense somewhere else.
Yes, I was camping. I had a SAW. What else are you supposed to do with it? It's a support weapon: USE IT FOR SUPPORT. Same thing with the M14, though you CAN run and gun with that to a degree. But yeah, that was a good game.