There's a lot of crossfire about guns these days. The Obama administration is under siege over Fast and Furious, a federal sting operation that allowed firearms to go to Mexican drug traffickers and was linked to the slaying of a Border Patrol agent. Meanwhile, Chicago is trying to get a handle on fatal shootings that have fueled an increased homicide rate, and the city and some suburbs are conducting gun buyback events this weekend.

1 Around Christmas 1928, Ernest Hemingway came home to Oak Park to attend his father's funeral and asked his mother if he could have the .32 caliber Smith & Wesson revolver that his father had used to kill himself. A few months later, Hemingway's mother shipped him the handgun, along with a chocolate cake.

2 Nearly half of Americans say a gun is kept in their household. This figure — 47 percent in a Gallup survey last October — was a six-point jump from a year earlier and the highest since 1993. Demographic groups that topped 50 percent included men, Republicans, Southerners, Midwesterners and people who had not gone to college.

3 In the infamous Valentine's Day Massacre, Al Capone's henchmen wielded Tommy guns, but the weapon's use by 1920s gangsters likely wasn't as extensive as popular culture and movies would lead us to believe. The gun was quite difficult to use and was dangerous to the shooter if he or she wasn't properly trained. A hooligan with a heavy trigger finger could empty one of those 100-round drums in just four seconds.

4 Clement Vallandigham, a former Ohio congressman, served as an attorney in 1871 defending a suspect accused of a barroom murder. Vallandigham theorized that the victim had in fact shot himself by accident while trying to pull a handgun out of his pants pocket. Conferring with colleagues in a hotel room, Vallandigham acted out his theory. He believed he was using an unloaded gun in his demonstration; he was wrong. But he was right about a gun going off accidentally; it did, and it killed him.

5 The Minie ball, developed by French officer Claude-Etienne Minie about a decade before the American Civil War, greatly increased the effective range of rifles. But some veterans failed to understand how warfare had changed. Just before Union Gen. John Sedgwick was fatally shot by a faraway sniper near the Spotsylvania Courthouse, he uttered his last words: "They couldn't hit an elephant at this distance."

6 John F. Kennedy was a member of the National Rifle Association.

7 It should be no surprise that the biggest gun ever built was created for the Nazi war machine. Krupp A.G.'s Gustav was truly a monster, weighing in at 1,344 tons, including its railway carriage. At four stories tall and 140 feet long, it required a 500-man crew. It could throw a 5-ton explosive shell 29 miles or an 8-ton concrete-piercing shell 23 miles. It was built to demolish France's famed Maginot line, but the German blitzkrieg rendered the Gustav irrelevant for that task. It was eventually used against the Soviets to wicked effect before it was captured by the Americans and cut up for scrap.

8 John Moses Browning designed a staggering number of famous guns, including the lever-action Winchester repeating rifle, the Browning automatic rifle (BAR) and the Model 1911 .45 automatic pistol. The son of a gunsmith, Browning was 14 when he built his first firearm, a rifle he gave to his brother.

9 Earlier this month, two Australian swimmers were barred by that country's Olympic officials from using social media during the London Games after the pair posted photos of themselves posing with pistols and rifles at a gun shop. Not only that, but Nick D'Arcy and Kenrick Monk will be forced to leave the Games early after they finish their events. It's unclear if athletes competing in the 15 medal events involving shooting would face the same punishment.

10 Some gun inventors, such as Richard Gatling and Mikhail Kalashnikov, have expressed regrets about their legacies. Gatling felt that his machine gun took attention away from his work on more peaceful innovations, such as seed drills and steam-driven plows. Kalashnikov, the AK-47 creator who is 92, is proud that his invention helped Russia defend itself but said "when I see (Osama) bin Laden on television with his Kalashnikov, I'm disgusted." And he admitted: "I wish I had invented a lawn mower."

Mark Jacob is a deputy metro editor at the Tribune; Stephan Benzkofer is the newspaper's weekend editor.

mjacob@tribune.com

sbenzkofer@tribune.com

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Sources: "Hemingway's Boat: Everything He Loved in Life, and Lost, 1934-1961" by Paul Hendrickson; "The Limits of Dissent: Clement L. Vallandigham & the Civil War" by Frank L. Klement; "A Life of Clement L. Vallandigham" by James Laird Vallandigham; "Guns in American Society" by Gregg Lee Carter; "The Civil War" by Shelby Foote; "Historical Dictionary of the U.S. Army" edited by Jerold E. Brown; "From My Cold, Dead Hands: Charlton Heston And American Politics" by Emilie Raymond; "Mr. Gatling's Terrible Marvel" by Julia Keller; "The Gun That Changed the World" by Mikhail Kalashnikov with Elena Joly; gallup.com; popularmechanics.com; espn.com.