In addition, each defendant is charged with participating in an organised criminal group.
The Rotorua-based Mangu Kaha gang has Black Power links, but operates as a separate entity.
In his opening address, Hill told the jury that after several days of verbal animosity between the two adversaries in the Western Heights suburb in December 2015, the situation erupted when 15 to 20 Mangu Kaha members advanced on a property rented by the daughter of a senior Mongrel Mob member.
He said Mangu Kaha considered the area its territory, some were armed with poles and bats obviously looking for a confrontation, Hill said.
Their adversaries picked up axes and batons ready to retaliate.
"George Jolley stepped forward with a double barrelled shotgun, pointed it into the opposing group and said 'come on you dog s***s, I'm going to kill you c***s', before firing into the group," Hill told the jury.
One man, Wade Pereira, was hit in the face. When the gun appeared to misfire, Dashwood grabbed and re-fired it, hitting the first victim's brother, Ben Pereira, in the shoulder and an arm.
"Everyone scattered, the business had been done," Hill said.
Despite Wade Pereira's serious injuries and his brother being taken to hospital, both refused to co-operate with police and wouldn't be testifying, Hill said.
The only defence lawyer to make an opening statement was Moana Dorset who represents Christopher Jolley.
She said he was never involved in any of three altercations on December 8, 9 and 11, 2015.
He'd been released from prison, where he'd been for driving while disqualified, 48 hours before the shooting and "unfortunately for him" the house he was paroled to was next to the scene of the confrontation.
"He was never outside that property on Turner Drive," she said.
The trial is before 11 jurors, after one was stood down. It is set down for four weeks.