A new study suggests that about a third of Americans have at least one gun, NBC News reported. Most are white males over the age of 55, and a "gun culture" is closely linked with ownership, the team at Columbia University behind the study reports. "One-third of Americans reported owning a gun, ranging from 5.2 percent in Delaware to 61.7 percent in Alaska," they wrote in their report. "Gun ownership was 2.25 times greater among those reporting social gun culture than those who did not." The study, published in the journal Injury Prevention, is one of several trying to pin down the number of gun owners in the United States. No agency keeps statistics on gun ownership and many pro-gun activists advocate keeping gun ownership private because of fears about potential future laws that might take guns away.