No real decline in percentage of American Homes containing firearms (?)

The latest results from the General Social Survey  (GSS), a well-respected survey operation, show that the percentage of homes in the U.S. containing firearms is declining.   Like many, I am skeptical of this result. This is in spite of tremendous sales of new guns and tremendous increases in people licensed to carry guns. How can this discrepancy be explained?   First, note that the GSS result are not consistent with some other surveys.  Second, the GSS is an in-person survey where there is no anonymity unlike, for instance, telephone surveys. This may cause many gun-owners, who distrust the government on gun control, to deny ownership.  Perhaps they are unsure about whether their ownership is legal.  "Further, (According to the Globe and Mail):
"In December, 2014, a survey by the Pew Research Center reported that for the first time in 20 years, support for gun rights was greater than support for gun control – and that since the Newtown tragedy in which 20 children and six school staff were killed at Sandy Hook Elementary School, support for gun rights increased from 45 per cent to 52 per cent.
The survey also pointed out that an increasing number of Americans believe gun ownership protects people from crime. In December, 2012, 48 per cent held that position. Two years after Newtown, 57 per cent believed guns save people from becoming victims of crime."  Further, according to the G&M:
"According to the 2014 edition of the General Social Survey, one of the largest general trend reports in the U.S., 31 per cent of households reported having a firearm. That’s the lowest level on record, tied with 2010, since the survey began standardized monitoring in 1972.
But at the same time, firearms sales appear to be as healthy as ever. According to the FBI criminal background-check database – often used as a proxy for measuring gun sales – checks have steadily risen over the past decade and a half, from 8.5 million in 2000 to nearly 21 million last year. Some of the sharpest spikes coincide with the election and re-election of President Barack Obama, suggesting a concern that a Democratic White House would move to limit gun rights – a concern that, for the most part, has not materialized.
But within the data, there is a more complex story. For years, the General Social Survey tended to show a significantly lower rate of gun ownership in the United States than many other surveys – a discrepancy that may be explained not by statistics, but by the basic mistrust of authority that appears to be a common denominator among the most fervent pro-gun advocates.
“The only thing I know that’s for sure different between the GSS and other polls is that the GSS is an in-home, face-to-face survey,” said Gary Kleck, a professor of criminology and criminal justice at Florida State University [and the nation's leading expert on guns, gun crime, etc.]. “What that does is make it a non-anonymous survey. You may say gun owners are paranoid for thinking it, but they think governments – and in particular the federal government – are out to get their guns.” Further, according the the G&M:

"Does everyone agree that it's declining?

Not entirely. “The big challenge for me looking at these numbers is that you have to be confident that people are going to report their gun ownership accurately,” said Samuel Bieler, research associate at the independent and non-partisan think tank Urban Institute in Washington. “And I think it’s an open question as to whether if a gun owner is already suspicious of someone’s motive for collecting firearm information, whether they’d be willing to do that,” he added. There are also Gallup surveys that point to spikes in gun ownership in recent years. “There’s enough noise and enough countervailing explanations that to me, the jury is really still in some ways out on the full amount of gun ownership,” said Mr. Bieler."

The rate of guns in the home is not declining.  What many suggest, including the G&M, is that the "gun culture" in the U.S. is becoming less of a sporting, hunting and collecting culture and more of a "self-defense culture".