I'm with Tipsy Dragon. I carbonated a batch a while ago to 3.25 volumes of CO2 by Tasty brew calculator. When I finished bottling, I found out I only had 4.5 gallons of beer, so needless to say, I was pretty nervous. More like 3.5 volumes of CO2! Turns out, 22 Bombers fit well in one of those Sterilite storage boxes. None blew, but I contained them for several months in preparation for the worst.
What I'm getting at is that you don't know how much residual sugar was left in your beer at bottling. 3 or 4 gravity points could be the difference between ridiculous head and glass shrapnel. Better safe than sorry, I say, and try to make sure your fermentation is over before bottling.