THE expedition leader who shot and killed the polar bear that mauled Horatio Chapple has told an inquest into the Bishopstone teenager’s death that he did not know why the rifle failed to fire four times.

Michael Reid, known as Spike, suffered severe injuries to his head and neck during the attack in Norway on August 5, 2011, during which 17-year-old Eton pupil Horatio was killed..

Mr Reid was the science leader of the Chanzin Fire group, of which Horatio was a member.

Salisbury Coroners Court heard today Mr Reid was an experienced explorer but had not been to the Arctic before. He had experience firing rifles in the Combined Cadet Force at school and in Officer Training Corps at university but had not fired the Mauser rifle leaders were supplied with until he arrived in Norway.

On August 4 the group returned to their camp at about 6pm.

Doing bear watch duty was discussed but Mr Reid and co-leader Andrew Ruck decided against it as the young explorers had had a hard day and another expedition was planned for the following morning.

The Chanzin Fire team made modifications to a trip wire system, which Mr Reid said was 100 per cent successful when they tested it.

On the morning of August 5, Mr Reid woke to shouts of 'bear attack' and emerged from his tent with the group 's Mauser rifle.

He said: "The bear was close and it was on top of one of the YEs (young explorers) in a sleeping bag.

"I cocked the rifle, took aim carefully and shot at the chest area of the bear but the rifle didn't fire."

Mr Reid repeated the process until the rifle's magazine was empty, which was four rounds, but each time the rifle failed to fire and ejected the round from the gun.

"The bear then came and attacked me. Because the rifle was then on the ground beside me, I shouted 'use your pen flares'. They're not easy to use and not safe to use in close quarters but I thought that would be safer than this bear carrying on.

"I remember the bear biting my head and thought the weakest part is the eyes, so I tried to take out the eyes with my fingers but was unsuccessful. Once it moved off me I asked "where's my rifle?" and someone said it’s in your tent."

Mr Reid retrieved the gun, picked up one of the ejected bullets and reloaded the rifle. This time it fired.

The injuries he suffered meant Mr Reid has limited memory of the incident and said he wasn't aware of where Horatio was during the attack but paid tribute to the Bishopstone teenager saying: "He was a fantastic member of our team, definitely one of the best, if not the best, in the whole expedition. He was a fine young gentleman with some amazing potential and a joy to be on an expedition with."

The inquest continues.