When Bradley Hoye was beaten with a tree branch and killed he was wearing a balaclava, was armed with two knives, had a blood alcohol reading of .195 and had traces of amphetamine and methyl-amphetamine in his blood.

The 32-year-old had been chasing a group of young men through the streets of Narrabri in northern NSW, after mistaking them for a group with whom he had had an earlier altercation.

He shouted after one of them: "You're that c***, I'm going to get you, I'm going to cut you up", the NSW Supreme Court was told.

When one of the group grabbed a tree branch and threatened to hit Mr Hoye with it if he did not drop his knives, he called for a truce and started to back away, the NSW Supreme Court has been told.

But one of the group, Ashley Duane Smith - who had also been drinking heavily and had smoked cannabis earlier that evening - took the branch and swung at Mr Hoye anyway.

Mr Hoye died at the scene after inhaling blood oozing from extensive injuries to his head and neck.

Smith, 23, from Wee Waa in the state's north, was charged with his murder, but towards the end of his trial in September he pleaded guilty to the lesser charge of manslaughter.

On Friday, he was sentenced to serve at least four and a half years in jail, with a maximum term of six years and nine months.

"Mr Smith swung the stick with both hands, and struck Mr Hoye in the head on at least two occasions," sentencing judge Justice Jane Mathews said.

"Mr Hoye fell to the ground. Whilst he was on the ground, Mr Smith again struck him with the stick at least once, and possibly more.

"He also kicked him around the head until one of his friends pulled him back ...

"The fact that he continued to strike and kick at Mr Hoye even after he was on the ground constituted an unnecessary and excessive display of aggression."

Justice Mathews said the death would most likely never have happened if it had not been for the alcohol both men had consumed.

"The killing of Bradley Hoye was a tragedy which never should have happened. It was a tragedy which was essentially fuelled by alcohol," she said.

"Mr Hoye was clearly seeking to vindicate a wrong which had been done to him earlier in the evening. In the process he became aggressive and belligerent to a group of strangers which happened to include Mr Smith and his companions.

"Similarly, Mr Smith's ... judgment was very seriously impaired. By the time he struck Mr Hoye with the tree branch, the latter was already retreating ... he no longer posed any realistic threat at all.

"It is highly probable that, had one or other of Mr Hoye or Mr Smith not been significantly affected by alcohol, this tragedy would never have happened."

Justice Mathews took into consideration Smith's lack of a criminal record, his youth, the mitigating factor of his alcohol consumption, as well as his guilty plea, when sentencing him.

"Clearly the offender has the potential to lead a productive and useful life," she said.

"It is hoped that he will use his time in custody in a constructive manner which will enhance his prospects upon release."

With time already served, Smith will be eligible for release on November 10, 2013.