In 2012, it was 730,000 gun owners, down from 765,000 in 2001, what is it today?
The number of legal firearms in 2012 was 2,750,000.
About 172,000 hand guns are owned by the people.
About a million. You get somewhat different figures from different sources - ranging from around 730,000 as you mention from a US study done by the Library of Congress, up to 1.2 million by a 2011 study done here in Australia by Bauer and English, so 'about a million' is a decent midrange figure.
The number of legal firearms in 2012 was 2,750,000.
Close enough - 3 million is a more common estimate, but that's not that different.
About 172,000 hand guns are owned by the people.
That's about right - these get counted properly, because of the category licences and permits, so that's a fairly solid number.