The jury had heard that Bracken had Mr Davis hogtied, left him tied up in a woolshed for about 20 hours, then beat him to death with a thistle grubber, leaving his body down a ravine off isolated Salvation Rd, near Kaeo.
Justice Edwin Wylie noted during sentencing Bracken had taunted Mr Davis' family by singing and whistling Candle in the Wind when he entered and left the courtroom during the trial, continuing even after being asked to stop.
"You were confrontational with witnesses and thought you were above the law," he said at the time.
"It was calculated and vicious. It was, in effect, an execution," Justice Wylie said of Mr Davis' death.
"You totally ignored his torment."
The starting point for sentencing was 20 years but he added another year for aggravating features, including Bracken's continued denial of wrongdoing, complete lack of remorse, his 18 previous convictions, several of them for violence, and the brutality of the killing.
The judge said Bracken was "dangerous and evil".
