In the UK, you are required to have a license for any firearm, and we haven't had any handgun licenses for many years (since the aftermath of the Dunblane shooting[1] in 1996.)
The only type of license that I know of as common is shotguns in the countryside. (I live in central London, and if I applied for a shotgun license I'd not only be refused out of hand, I'd probably go on every police watch list that exists.)
Let's be clear, the UK hasnt banned all handgun sales to civilians. Black powder is still allowed, as are small firearms in special circumstances. I suspect you are referring to "modern" handguns. In which case, subjects of the crown are not allowed to own them. Whereas, Handgun sales to the government are very common, and of course Illegal handguns are certainly sold in the UK to criminals. So there have been handgun sales in the UK since the "ban".
Err, yes, but I don't think anything you've said actually disproves his argument...
Black powder guns - I assuming you're referring to the muzzle-loaded antique-looking ones you'd normally see in museums?
Not exactly the sort of thing you'd use for sport shooting, or for self-defense.
And saying that there are illegal sales doesn't mean that the "UK hasn't banned all handgun sales to civilians".
That's like saying smoking in a hospital is illegal - but I heard from a friend of a friend that this guy in the next county did it once and didn't get caught - so they haven't really banned smoking, have they gasp?
Look, I have my own thoughts on guy laws, and I'm not saying the UK handgun ban is bad - but to claim is isn't really a ban (with tiny exceptions) is a bit disingenuous.
The only type of license that I know of as common is shotguns in the countryside. (I live in central London, and if I applied for a shotgun license I'd not only be refused out of hand, I'd probably go on every police watch list that exists.)
[1] http://en.wikipedia.org/wiki/Dunblane_school_massacre