Splash damage radius is 1.5-1.6 meters, but any serious damage can be done only with really near shots. A shot near soldiers head should critically wound him (make him bleed) or kill him if you're lucky. Radius and damage is big enough to wound / kill APC or AT guns crews when you land a shot on a shield or armor plate next to their faces. As eat Eat Uranium said, explosive ammo will be always a 1s1k on all hits, no matter the body part and distance. On top of that the suppression radius is 2.5 meters.