Auckland, May 28 NZPA - A man who accidentally shot dead his girlfriend with a sawn-off shotgun last year has been jailed for three years four months.

Justin Paul Goldstone, 21, was sentenced in the High Court at Auckland today by Justice Forrest Miller.

Goldstone admitted the manslaughter of his partner of six months, Samantha Joanne Henderson, 20, when he appeared in North Shore District Court in February.

He also pleaded guilty to the unlawful possession of a cut-down shotgun. He was jailed for six months on this charge, to run concurrently.

Sentencing Goldstone, Justice Miller told him it was hard to imagine a more reckless act than pointing a gun at someone with your finger on the trigger.

"You acted recklessly by pointing the gun at the camera, which defies belief. You had your finger on the trigger when you were posing for photos and you didn't have the safety catch on.

"I'm satisfied that you didn't use the gun deliberately but you did know the gun was loaded," Justice Miller said.

Ms Henderson died on December 4 last year as Goldstone posed for a series of pictures with a sawn-off shotgun which police said he had acquired for their protection.

She had asked him to pose after he got the loaded shotgun from an attic space where it had been stored.

Ms Henderson took several pictures with her digital camera, showing Goldstone with his finger resting on the trigger as he pointed the shotgun at the camera.

The shotgun discharged and the blast hit Ms Henderson in the head with shotgun pellets going through the camera.

The blast caused "massive trauma to the left side of her head," said police in the summary of facts.

Goldstone dropped the shotgun and went to her aid, but Ms Henderson was unresponsive.

He put her in his car and took her to a medical centre but refused to give a statement to police for three days.

He said he believed his finger was outside the trigger guard and not resting on the trigger.