I always revert back to two questions regarding gun control:
1. Can you name one law that would keep guns out of the hands of law-breakers?
2. OK - Assume that somehow you've removed non-military gun ownership from all but the police. How do you stop: "Hello, I'm a policeman, this is my gun - hand me your wallet."?
Not to disparage police officers, but what really protects our rights? I believe we each have to protect our own rights. This is very difficult without guns. Police exist to figure out who's the bad guy and collect evidence AFTER an altercation, not to dive through your doorway shooting bad guys caught in the act like on T.V. I commend the work of the police force, but there's no possible way they can stop all crime.
In your discussions, you may get to the "giant magnet" theory. This is where you somehow remove all guns from the face of the earth - like with some sort of giant magnet.
Before guns existed, strong men with fists, sticks or swords grouped together under a leader to force their will upon others. People banded together to fight back.
If you were just trying to live your life -- maybe trying to farm some land, you needed the protection of the united forces of your neighbors to come and fight with you if invaded. This system is most efficient under a heirarchy that manages multiple chunks of farmland backed up by a brute force of bodies to protect it. This leads to kings, dukes and knights to collect taxes and alliegence in exchange for protection from the barbarians next door - first through brute force and later through negotiation and periodic wars.
Guns take brute force out of the equation. Almost anyone from 7 to 100 can aim and shoot a gun to deter an attacker. Just one experienced person with a good rifle can hold off a horde of invaders.
Guns changed the world. America grew up without a need for protection through kingdoms and feudalism.
Some would argue that times have changed and we don't need guns any longer in our sophistocated world. I argue back that Europeans in the 1920s seemed to think that they were extremely sophistocated and many probably didn't think they needed guns after "The War to End All Wars".
Many who thought this were exterminated by armed monsters.
If you look at
www.JPFO.org as suggested above, you can find that an average of more than 2000 unarmed men women and children were murdered by their own government for each day in the 20th century -- after gun control laws disarmed them.
I hope this helps. Good luck and keep shooting safely!