Two Public Safety Team officers went to the Onekawa house about 6.45pm on Tuesday looking for a 19-year-old man who had a warrant for his arrest.
As the pair approached the house they saw a firearm through a window, prompting a search of the property, police said.
Police said they found a AK-47 machine gun, a pistol, ammunition and 5.5kg of methamphetamine.
Eastern district crime services manager, Detective Inspector Martin James, said the amount of methamphetamine was significant, equivalent to an estimated 275,000 doses.
If sold on the streets it would be worth about $2.2 million.
"This was exceptional work by the officers involved," he said.
"They were at the property to undertake a fairly routine policing task, but they were also focused on the bigger picture."
Two patched gang members aged 19 and 34 were arrested and face a number of drugs- and firearms-related charges.
They were due to appear in Hastings District Court on Wednesday.
