An injured moose bull attacked a hunter and climbed at the rifle so a shot went off.
The bull moose was injured and the hunters dog had made it stand. This is the technique used for hunting moose in Scandinavia. The hunter was only 15 meters away from the moose when it attacked. A moose is normally not dangerous so this is extremally unusual. The moose gored the hunter in the chest and climbed on the rifle. The rifle went off and then broke into two pieces. The moose was lucklily enough hit by a deadly bullet so the hunter could a bit chocked escape.
See another moose attack at Youtube