It takes a gun to stop a gunman

Every time we have a massacre, Democrats demand new gun control laws. A few observations:

i) What causes a gunman to stop shooting? In my observation, it's generally one of two things:

a) He runs out of ammo

b) Someone shoots him

So it takes a gun to stop a gunman. Having a gun gives the shooter a nearly unbeatable advantage over unarmed targets. It's hard for unarmed men and women to stop or disarm a gunman.

Occasionally, a gunman will shoot himself to elude capture. That's after he's completed his shooting spree. 

ii) What's the alternative? That only police have guns? If so, there are obvious problems with that:

a) It's my observation that most folks who lobby for gun control are often very critical of police shootings. 

b) If only the police (and military) have guns, doesn't that put the general public at a tremendous disadvantage with respect to gov't? What's to prevent gov't from acting like a bully? You can't fight back. Gov't has all the firepower. 

c) Suppose a gunman begins to shoot up a school or office or whatever. Suppose someone inside manages to call the police.

It takes the police however long to arrive at the scene of the crime. Moreover, they don't rush right in. They take time to position themselves. Study exits and floor plans.

That gives the gunman lots of extra time to keep killing people inside.

iii) Are gun-control advocates proposing gun confiscation? After all, if you think gun ownership should be restricted to law enforcement officers (and the military), how do you make sure that only the police are armed? How do you get all those guns off the street? How do you make sure guns are in the "right hands"? 

So does that mean gun-control advocates think police should ransack every house, warehouse, car, truck, boat, business, &c. in America in search of guns? 

iv) Even if you outlaw gun stores and gun shows, won't that simply create a lucrative black market for gunrunners? You will replace legal arms dealers with illegal arms dealers.