Key point: Today, the Gyrojet weapons are collector’s items. In the 1960s an American engineer and his partner invented a gun that fired rocket-propelled ammunition.

Almost as light as a highball tumbler, silent as a hummingbird's flight—yet with twice the wallop of a .45—the Gyrojet rocket handgun sounds like the secret agent's dream. Costing ...

Suicide is the leading cause of gun-related deaths in the United States. But it's often only an afterthought in the public debate about gun violence.