Shot fired from an AK-47 using Schlieren photography.  This method “involves shining collimated light past a knife edge onto a target, and variations in the refractive index of moving air create ‘shadows’ of a sort in the image captured on film…[I]t’s most often used to solve aeronautical air-flow problems, or weapons in action.” Via Gizmodo, which has a gross, yet fascinating, picture of a cough using the same technology.