LEIGH SALES, PRESENTER: America may be on the brink of introducing historic limitations to gun ownership.

President Barack Obama has unveiled reforms making it harder to get assault weapons, after a gunman killed 20 children and six teachers at a school last month.

But he'll face a tough battle to do everything he wants.

The powerful gun lobby is mobilising all its forces. Take a look at this advertisement from the National Rifle Association.

(excerpt from NRA advertisement)

NARRATOR: Are the president's kids more important than yours? Then why is he sceptical about putting armed security in our schools when his kids are protected by armed guards at their school?

Mr Obama demands the wealthy pay their fair share of taxes but he is just another elitist hypocrite when it comes to a fair share of security - protection for their kids and gun-free zones for ours.

ONSCREEN TEXT: NRA. Stand and fight.

(end excerpt)

LEIGH SALES: Many Australians find the US gun debate hard to fathom given the success of gun reforms introduced here by the former prime minister John Howard after the Port Arthur massacre in 1996.

For insight into America's pro-gun mindset, I was joined earlier from Virginia by the president of the Gun Owners of America, Larry Pratt.

Larry Pratt, what do you think of the reforms announced by president Obama today?

LARRY PRATT, PRESIDENT, GUN OWNERS OF AMERICA, VIRGINIA: It's what we might have expected from someone coming from his point of view and what he's not at all discussing is the fact that the mass murders that have occurred in our country over the last 20 years have occurred in precisely the kind of gun-free zone that was legally in force in Newtown, Connecticut.

LEIGH SALES: Massacres have occurred all over the United States, from Virginia to Arizona to Colorado. It is inaccurate and misleading to say that they have only occurred in gun-free zones.

LARRY PRATT: These were places that occurred at schools which legally were gun-free zones, or the theatre in Colorado was the one out of some seven near where the murderer lived which was posted no guns, and so he chose exactly what he was looking for and I think we have to conclude that gun-free zones are like magnets for these people.

LEIGH SALES: Why would any civilian need a military-style assault weapon with a high-capacity magazine?

LARRY PRATT: They're not military style and they're not assault rifles. They are defence weapons. They've been used by Korean merchants when there was no public order in Los Angeles for days during the LA riots.

They were used following the breakdown of social order following Hurricane Katrina and average citizens have used them on several occasions when hurricanes in south Florida have simply imploded the normal order of society, police are nowhere to be seen for sometimes days on ends, and so people are on their own.

LEIGH SALES: What do you think will happen if the US government puts restrictions on gun ownership?

LARRY PRATT: Well, there are politicians that think that it's their job to rule us and it's our job to be ruled and it's kind of a basic impulse and that's why we continue to vote politicians out of office because they get a little full of themselves.

And particularly among Democrats, although not exclusively, we find a tendency to want to control guns because they just don't like the idea of an armed populace but of course our second amendment says that's exactly why we are supposed to have an armed populous, so that the Government is mindful that there's only so far it can go and the people can protect themselves against tyranny.

LEIGH SALES: But with this armed populace argument, if we take it to its logical conclusion, even if every American had as many weapons as they like, the United States government and its army is always going to have more weapons so therefore no matter how many weapons you have, you're still going to be defeated so therefore it's a spurious argument to make.

LARRY PRATT: Well, that remains to be seen. There have been confrontations before. Actually when we started our country we beat the army of the most powerful empire in the world and we beat them with, starting with our muskets.

We have reason to be concerned about our government because it's our government that was running guns deliberately into the hands of the Mexican cartel and the scandal that I'm sure you know of called fast and furious. It's led to the murder of some 400 Mexicans and counting, two of our federal agents, and so it's rather stunning that a government that would perpetrate such a monstrous crime is now telling the American gun owner, "You can't be trusted. We need to have more control over you." I don't think so.

LEIGH SALES: In Australia, the government reacted to a massacre in 1996 by banning the sale, importation and possession of semi-automatic rifles and by removing 700,000 guns from circulation.

In the 18 years before that we had 13 massacres. After that we had zero. We didn't have a civil war, the government didn't come and take all of our stuff away from us. Why not just give it a try in the US?

LARRY PRATT: Once you've given it a try there's no going back and so in the United States we're not going to do that. In the United States we are citizens in control of the government and as the Swiss say to this day, a rifle is the emblem of a free man.

LEIGH SALES: But it worked in Australia. Why not just try it?

LARRY PRATT: Your violent crime rate is not so admirable and besides...

LEIGH SALES: It's a lot lower than yours.

LARRY PRATT: We're not interested in being like Australia. We're Americans.

LEIGH SALES: Pro gun activists want to see armed teachers in schools but in chaotic situations, highly trained police officers shoot and kill the wrong people. In war zones, highly trained soldiers shoot their own colleagues in friendly fire incidents.

What makes you think that a primary school teacher is going to be able to take out a mad gunman without killing children?

LARRY PRATT: Well the armed teacher is going to have a lot more chance stopping a mass murderer than the police who take 20 minutes to get there, as they did in Newtown, and that's not an extraordinarily long response time. That's just the way life works and so to tell somebody that we think no defence is a good defence is morally indefensible and we're not going to tolerate that.

LEIGH SALES: There have been 62 mass shoots in the United States in the past 30 years. Not one has been stopped midway through by a civilian.

LARRY PRATT: The ones that did get stopped don't make the list of 62 now, do they?

LEIGH SALES: I'm saying that there has not been a shooting where four or five people have been shot and then an armed civilian has come in and started shooting and averted disaster.

LARRY PRATT: What you're saying is that you're not accepting the fact that some of the shootings that have occurred were stopped before they could become what qualifies as a mass murder, four or five people that have been murdered and that has happened fairly frequently.

It happened at a mall just three days before Newtown. In Clackamas, Oregon, near Portland, a man went into a mall that was marked "no guns" and he killed two people, wounded a third.

Another man, who had a concealed carry permit, was also in the mall, heard the shots, came running to the scene of the crime. Happily, the murderer's gun had jammed and he was just getting it un-jammed when the good guy with a gun got there.

When the murderer saw him approaching, he killed himself. End of problem. Never got to be a "mass murder" but it certainly had every look of something that was going to be a mass murder had not the good guy with a gun gotten there in time.

LEIGH SALES: Larry Pratt, thank you so much.

LARRY PRATT: Good to be with you. Thank you.