Well, I suppose if one were a fan of despot leadership like Hitler and Karl Marx, one significant advantage of banning (not "banding") handguns would be that it would be much easier to enforce their totalitarian agenda on the citizens.
And, if one were a robber, banning handguns would make like simpler and safer while plying their chosen trade.
No one on this board will agree, but you will hear how banning handguns would prevent accidental shooting deaths [especially "the children"]. You will also hear how criminals would not be able to steal handguns to use in criminal activity if no one had a handgun.
Neither of these arguments are based upon real data. In fact, the opposite is true: Taking handguns away from law abiding citizens makes it easier for criminals to do their thing.
England tried it and it just does not work.
I understand that you need to make the argument in your debate class.
You probably should check the Brady Campaign or the Stop Handgun Violence web sites if you must present such arguments.