Gun enthusiast Paul Gwaltney at Blue Ridge Arsenal, in Chantilly, Va. Gwaltney, an NPR listener, agreed to host a discussion about guns with friends and colleagues. Becky Lettenberger/NPR hide caption

itoggle caption Becky Lettenberger/NPR

Customers shop for guns at Freddie Bear Sports sporting goods store in Tinley Park, Ill., in January. One of the gun provisions in the spending bill prevents the Justice Department from requiring gun dealers to conduct an inventory to see if guns are lost or stolen. Scott Olson/Getty Images hide caption

itoggle caption Scott Olson/Getty Images

Chris Colwell, director of emergency medicine at Denver Health, has treated victims from two of the deadliest mass shootings in the U.S. He says he's deeply disturbed by how easy it is to get guns. Barry Gutierrez/for NPR hide caption

itoggle caption Barry Gutierrez/for NPR

Vice President Biden at a December 2012 meeting of police chiefs on gun control, held in Washington, D.C. Carolyn Kaster/AP hide caption

itoggle caption Carolyn Kaster/AP

Dr. Frank Dumont at his clinic in Estes Park, Colo. Barry Gutierrez for NPR hide caption

itoggle caption Barry Gutierrez for NPR

Gun enthusiasts take part in a shooting competition at a club outside Zurich. The gun culture is deeply entrenched in Switzerland, where citizens as young as 10 learn to shoot. Soraya Sarhaddi Nelson /NPR hide caption

itoggle caption Soraya Sarhaddi Nelson /NPR

Connie Jacobson, coroner in Natrona County, Wyo., says suicide is one of the biggest public health problems facing the state. Wyoming has the highest suicide rate in the U.S., and two-thirds of suicides in the state are by firearm. Kirk Siegler/NPR hide caption

itoggle caption Kirk Siegler/NPR

Led by the Rev. Willie Phillips (center), protesters march in February against violence in and around Club Majestic. Mike Haskey/Courtesy of The Ledger Enquirer hide caption

itoggle caption Mike Haskey/Courtesy of The Ledger Enquirer

This 9 mm semi-automatic handgun is configured with transducers in its handle that can detect the grasp of an authorized user. New Jersey Institute of Technology/AP hide caption

itoggle caption New Jersey Institute of Technology/AP