Sands

There's a difference between a gun-attack and a gun-threat. You're not likely to survive a gun-attack because, obviously, if the person wants you dead then they're going to stand 10 to 15 feet away from you and shoot you until you stop moving.

A gun-threat, on the other hand, is when an assailant uses a firearm in order to leverage you into giving in to their demands for either valuables, or your body (if they want to kidnap or rape you, or both).

It's this situation that Krav Maga will try to prepare you for... overwhelming and disarming a gun-man that's within range. It's better than a heel-hook.