During the war in Vietnam, the US made special ammunition for revolvers in which the bullet casing contained a piston that was kept captive after it propelled the bullet forward. The fired gases were not allowed to exit the casing, and the gun made very little noise. They were used by the men who went into the tunnels after NVAs, after using a conventional firearm proved pretty difficult. The Soviets also had similar cartridges. Short range option, but good enough in certain situations.