Switch weapons?
You have two for a reason.
But that split second can sometimes be the death of you.
I mean tbh when this happened in MAG, the pistols were hardly a viable option because although they were powerful, they had TERRIBLE irons and very slow fire rates. In CQC it was insanely hard to make the shots hit if you were both Light guys strafing around, and anything beyond close range was just as hard.
MAG got me into the habit of favoring larger mags, and I incorporated it into my play-style. Admittedly it will be easier in Brink, especially as a medium/heavy, but then you still have to actually swap your weapon. Swapping is faster than reloading, but you never have to do EITHER mid-firefight with Extended Mags.