Military-style assault rifles have become the latest weapon against terror and organised crime, with specialist police now trained to use the semi-automatic weapons "in the most difficult situations" across the state.
NSW Police Commissioner Mick Fuller announced on Monday that 47 officers from the Public Order and Riot Squad had been issued with the Colt M4 carbines and the squad's other 50 members would be trained by the middle of next year.
The firearms, which are described by its manufacturer as the "United States Armed Forces' weapon of choice and the weapon of the 21st century warfighter", would be carried by officers in the small, mobile teams as they made their patrols across Sydney.
That would include New Year's Eve celebrations.
But Mr Fuller said the guns would not be seen by the public in general street patrols "at this stage" unless there was a change in the current terror threat, which has remained at a "probable" level since September, 2014.
"One of the keys is if there was a change in the threat level from probable to higher then there is no point saying to you 'I want to have a long-arm capability'," he said.
"So I suppose the first [step] is if there was a change in the national terrorist threat level then I can put long arms on the street today."
He later added: "We are ready to go. If there was a specific threat somewhere they would be deployed either in a preventative way or a destructive way or we can respond.
"So we certainly won't hesitate in using them and perhaps next year, depending on the environment, you may see officers deployed in a standard patrolling type method with these types of firearms.
"But we need to talk to the community about that and we need to let people know that this is just a changing environment.
Mr Fuller first announced the introduction of the assault rifles in July following lengthy research to identify the right type of weapon and training.
Deputy Commissioner (Investigations and Special Tactics) Dave Hudson said the 10-day training program had been "acknowledged as world's best practice" and was on top of the four-day "active armed offender" training recently undertaken by all frontline police across the state.
Mr Hudson said the general duties-issued Glock pistol was shown to be less effective in incidents "over 25 metres" and research had shown "most incidents overseas have occurred at a distance over 25 metres and up to a distance of 100 metres".
"Obviously the carrying of these firearms creates a deterrent effect as well, as well as resolving an incident," Mr Hudson said.
"So based on the nature of the incident that we are responding to, or the public issue that we are attending, there may be a need to sling these firearms and for the Public Order and Riot Squad to forward deploy with them.
"That will be an assessment made on a case-by-case basis based on a number of situations and circumstances which will feed into risk assessments."
Police Minister Troy Grant acknowledged there could be some criticism levelled at the introduction of the weapons.
"There may be some in our community who may be confronted by the fact that police now have a greater capacity in relation to their firearms and their arsenal," Mr Grant said.
"But I think more so, the community will be comforted by the fact that police have that capability to keep them safe.
"It is a reality that the world we live in is changing. We wish we didn't have to move down this path and we hope that these firearms will never need to be used.
"That is our sincere hope."
Mr Fuller said there was no immediate plan to have the guns available to the rest of the state's police officers, including having them carried in general duties vehicles.
"It is certainly possible, but certainly not in the coming months. We need to have that conversation," he said.
