Pure madness specs can put out a lot of steady pressure (just not burst). You've got literally 4 dots (don't forget force slow) you can throw on them.
You're basically a dotting machine, while keeping them at bay with 50% slowing force lightning and getting in your death fields as much as possible.
One of these days I'll actually give 31 point madness another go, but I actually rolled my sorcerer on day 1 (or -3, if you will) for the specific purpose of healing, so I've kinda stuck with that all along. I just eventually gave up 31 point heals for 21-ish.
Honestly, the most fun I've had with sorc in warzones is the heal/madness hybrid I came up with. Note I said fun, and not specifically ranked recommended (which is unfortunate):
limited CC, but you can actually switch back and forth from healing to DPS as required by the second to help burn down those last couple ememies and get that node/plant that bomb/etc.