All three had previously pleaded guilty to the charges.
The charges came as a result of Operation Rubicon on December 15, 2015 which police carried out at a Mamaku address in response to gang tensions and a shooting on Turner Drive in Western Heights four days prior.
Peter William Smith and Daniel Tere McMeeking were sentenced on similar charges, laid as result of the operation, in May 2016 and September 2017 respectively.
The men, associated with the Mangu Kaha chapter of Black Power, were found at the Mamaku address where they were anticipating retaliation from another gang, Judge Snell said.
There were a number of firearms on the property, though none of the men present had a firearms licence.
Te Aho Snr was seen by police patrolling the grounds holding a single barrel shotgun, "acting in capacity as sentry".
Daniel, Cramer and Grant McMeeking were all inside the property, where firearms were found, "some out in the open and loaded".
"These were easily accessible and ready to fire," Judge Snell said.
In sentencing the trio, Judge Snell said Cramer McMeeking had impulsive control issues and anti-social behaviour, Te Aho Snr was regarded as being at high risk of reoffending and Grant McMeeking had minimised his involvement.
"It is widely accepted that a gang-related incident poses significant risks to innocent members of the public.
"All of this offending had arisen in a gang context... A mix of gang-involvement, firearms and ammunition creates a risk of serious harm."
Two other men appeared before Judge Snell, but their charges were dismissed.
