Your precious gun bans 'dont stop those from being in the hands of criminals... So why do you think more of them will help?
Gun ban and gun regulation isn't the same thing.
In northern Europe guns are heavily regulated and they don't have nearly as much violent gun crime as the U.S.
This might not necessarily be because of gun regulation, not having gun nuts around is probably the big thing but I don't think killing them off is an acceptable solution.
The vast majority of gun crime in the US is related to drugs or gang related. 50% of the gun crime in the US is perpetrated by 4% of the population in the 7 largest major cities (several of which have total gun bans already - New York, Chicago, etc). The gun crime in these areas is similar to that of other countries which have total gun bans, such as Mexico, Russia, Brazil, etc. These countries (and parts of the US) have high gun crime not because of lax gun laws, but because of a degradation of the rule of law and civil society. Most parts of the US, especially rural areas, have far less crime than anywhere in Europe.