Hunter tries to shoot grizzly bear, bear knocks gun out of his hand and badly mauls him

Tom Sommers was bitten and slashed in the head by a grizzly bear: AP
Tom Sommers was bitten and slashed in the head by a grizzly bear: AP

A hunter was mauled by a grizzly bear after the animal swatted his pistol away as he tried to shoot it in the neck.

Tom Sommer said he could “hear bones crunching” as the bear bit his thigh and slashed his head during the attack in the US state of Montana.

The 57-year-old and his hunting partner used a type of pepper spray to defend themselves against the charging bear after disturbing it as it feeding on an elk during a hunting trip in the Beaverhead-Deelodge National Forest.

But Mr Sommer was left with only a pistol to defend himself after failing to release the safety catch on his own spray.

"The bear just flat-out charged us," he said.

"It bit my thigh, ran his claws through my wrist and proceeded to attack my head."

His hunting partner managed to deploy the rest of his bear spray, ending the 25-second attack.

Brown bear (grizzly) (Ursus arctos), Montana, United States of America (Rex)
Brown bear (grizzly) (Ursus arctos), Montana, United States of America (Rex)

“Just like that it stopped. He stopped biting me, he got up and started to run away,” Mr Sommer said.

“It could have been a lot worse.”

(Tom Sommer via AP)
(Tom Sommer via AP)

He was left with a 41-centimentre head wound and the pair had to walk for a mile and travel on mules to reach a hospital, where he was given 90 stitches.

“Through it all I was very conscious, very level-headed and low key about it," Mr Sommer said.

"Besides some scars, it doesn't appear that I will have any problems.

"I've been a hunter my whole life. I have no grievance against the bear. He was just doing what bears do. But I would have shot him just the same."