At the Guns and Ammo Warehouse they are reluctant to admit Barack Obama is right about very much. But customers enjoy the thought that his controversial campaign comment, that "bitter" small-town Americans are clinging to their guns, has proved more true than the president could have imagined.

Firearms sales have surged in the six months since Obama's election as millions of Americans have gone on a buying spree that has stripped gun shops in some parts of the country almost bare of assault weapons and led to a national ammunition shortage.

The FBI says that since November more than seven million people applied for criminal background checks in order to buy weapons, a figure excluding the many more buying at thousands of gun shows in states such as Virginia, without facing any checks.