From The Truth About Guns:

America is waking up to the notion that rights aren’t the only thing reserved for individuals. Responsibility to exercise those rights is shouldered by individuals as well. More than six million background checks were conducted in three months for the sale of a firearm. NSSF retailer surveys discovered nearly 2.5 million people became a first-time gun owner during that time.
That starts at the gun counter. The ability to exercise the right to keep and bear arms starts when law-abiding citizens are free to purchase the firearm they choose to defend themselves and their loved ones. Government interference with that constitutionally-protected right is nothing short of infringement. Deny the right to legally purchase a gun and it’s a violation of a constitutional right, just as it would be for a government to illegally search and seize property or illegally silence free speech.