Here is a list of people that support gun control, with data on how many people they murdered.
Adolf Hitler: Murdered 20 Million people, instituted gun control first
Joseph Stalin: Murdered up to 100 Million people, used gun control
Mao Zedong: Murdered up to 100 Million people, he used gun control
Pol Pot: killed 1/3rd of the population of Cambodia, used gun control to do it. 5 Million dead.
Ku Klux Klan: Murdered 4700 by 1968 Started gun control in the USA in order to disarm blacks.
If you agree with all of the people and groups listed above then maybe you need to question whether you are really on the right side of this issue. Being lumped together in that group of mass murderers would not make me comfortable.
The point has been made many times that if the Jews had been armed they could have resisted Adolf Hitler's "Final Solution". I've seen gun control advocates laugh at this statement as if it were ridiculous. The only thing ridiculous is the gun control advocates and their total lack of historical knowledge on a subject as important as the Holocaust. Read up on the Warsaw Ghetto Uprising of 1943 to see what I mean. In this uprising Jews who did still have a few weapons held 2000 Nazi SS troops at bay for four weeks. If only the Jews had been well armed the Nazi's would have been wiped out before they killed even a million Jews. The Jews proved they had the motivation, the courage and the skill to resist in Warsaw. What they lacked was the equipment.
The Nazi SS outnumbered the armed Jews 10 to one, and the Nazi's had tanks and better equipment. The Jews still held them off for four weeks and inflicted heavy casualties with only 200 guns. If you take the Warsaw uprising as the basis, and extrapolate what the Nazi casualties would be if Jews were armed at the same rate as american citizens, then you will easily see that the Nazi SS which had a total of 1.2 million members would have run out of soldiers due to casualties before they finished murdering 2 million total people. Since they killed around 20 million (6 million of which were Jews) this is only 10% of the total the Nazi's actually killed. Hitler would have killed about 2 million innocent people, and about 600,000 of them would have been Jews. That would have been a resounding success in stopping tyranny. Too bad the Germans didn't have the 2nd amendment. It almost certainly would have worked to stop the holocaust.
Here is a study going over all counties in the United States from 1977 to 1992. It shows that concealed carry has a significant effect in reducing crime.
Lets address the argument that the second amendment is only for muskets. First of all it is an offense to English grammar to try to say that the simple text of the 2nd amendment means that. If the framers WANTED to say only muskets they could have changed only one word to do that. They could have said "the right to keep and bear MUSKETS shall not be infringed". They deliberately used the general word ARMS instead.
As to the argument that they didn't know about rapid fire weapons, that is simply wrong. Rapid fire weapons existed as early as 1600. Here are some of the early rapid fire weapons that existed prior to the ratification of the US constitution in 1788: Stopler Revolver (1597), Kalthoff Repeater (early 1600's), Cookson Repeater (1680), Puckle Gun (1718), Belton Flintlock (1777), Girandoni Air Rifle (1779)
Here is an interesting story about Robert F Williams who started a chapter of the National Rifle association in order to protect his town from the KKK.