1911 junkie has wikepedia on his side, but I knew what driving bands were long before the internet was running down some bodies mamma's leg. The wiki version does indicate the term from military artillery shells having a specific band of softer material for the mating of shell to bore. Then go's on to say as 1911 said, " a rifle bullet is it's own driving band " then what do you call a bullet with grooves cut concentric to the bullet, with gaps in between?? Of course driving bands, not band. We have always used the term, for bullets without grooves, " surface area " A bullet without grooves has more surface area, in contact with the bore, than one with grooves in a similiar bullet design, ergo less friction, if they are both the same diameter, even less friction if the bullet has lubrication in those grooves.
http://tbn2.google.com/images?q=tbn:xHROfmuQNAjUkM:http://members.aol.com/SCOLL63101/public/GS1http://www.lima-wiederladetechnik.de/7,62-mm/Bilder/7,62-mm-DJG-1.jpghttp://www.hurog.com/images/silver/fired_bullets.jpghttp://dutchman.rebooty.com/images/bullet2.jpghttp://www.gsgroup.co.za/magnumhv.jpg Notice in the photo that they have concentric rings, called driving bands, on the shank and only these match the groove diameter of the barrel. This means that the lands engage (‘bite’ into) far less copper than with conventional bullets. HVs thus build up pressure slower and in general, achieve higher velocities than conventional bullets of similar weight in any given calibre. Gerard claims that the reduced bearing surface is not the only reason why his bullets are faster, but as the explanation of this is very technical I suggest that you contact him for further details. The above information is basically all the average reloader needs to know.
The point is, driving bands are exactly that or We would not have a definition, separate bands that reduce friction with or without lubrication. They make a huge difference in cast lead bullets. Bearing surface on the other hand also makes a huge difference, 9mm bullets come to mind 1st, hollow point will always have more bearing surface over a solid, in a given bullet weight and usually more accurate, the VLD bullets have much more Bearing surface + Higher ballistic coefficient = more potential for accuracy.