The pair have been trying to find black bear close to the household’s cabin after they noticed the 200lb (91kg) bruin.
Owen shot and injured the animal, which ran off into dense forest.
They gave chase, and as they entered a glade the animal charged at Mr Beierman from about 6ft (1.8m) away.
He mentioned he fired eight pictures on the bruin along with his pistol, however missed.
The bear bit him within the stomach, arm and leg.
“I began pistol-whipping him and it felt like I used to be hanging a brick wall,” he advised the newspaper, exterior.
He described seeing the flash from the muzzle of the boy’s rifle.
“I used to be flat on my again and will really feel the bullet going by the bear,” Mr Beierman mentioned.
He required stitches to reattach a flap of pores and skin to his cheek, and had puncture wounds to his arm and legs.
Officers say bear assaults are very uncommon.
9 such incidents have been reported within the state between 2013-22, in accordance with the Wisconsin Division of Pure Assets.