Jarron Paul Walker, 34, and Joshua James Walker, 27, pleaded guilty to making a threatening demand and unauthorised possession of a firearm about a week before their trial was scheduled in March.

A desire to protect family motivated the crime, the court heard.

Wearing balaclavas and carrying a loaded rifle, in 2014 the pair went a house in Chisholm, where Joshua's teenage cousin was being harassed by a former girlfriend's former partner, also teenagers.

The former partner was driving around the property, in one instance yelling from his car saying he wanted to fight the cousin, the agreed statement of facts say.

The former partner pulled up and parked outside the home when the ex-girlfriend open the car door and "deployed a 'fart bomb'," documents tendered to the court say.

The former partner got out of his Subaru, asking a small crowd of people on the front lawn where Joshua's cousin was.

Jarron and Joshua then approached the car from behind a tree and when one of them hit the windshield with the gun the rifle flashed and banged and the windshield shattered.

One of the offenders told the former partner the next one was "for you if you don't leave us alone" and to "smell the barrel" of the gun.

It was noted that neither had revealed which of them was carrying the gun, a detail that appeared to show they did not feel full remorse for the offence, Justice John Burns said.

In a courtroom full of supporters, Justice Burns suspended the pair's prison sentences leaving them to walk free on Monday.

The court heard Joshua's mother gave birth to him when she was 16-years-old. He was passed off to different family members and spent time in a youth refuge until at age 14 his uncle Jarron, only seven years older at 21, took him in.

But Joshua had "actually made good" with his life, the court heard, while Jarron was a deeply involved member of the community.

But Justice Burns highlighted the pair's "father figure" relationship.

"[Jarron] you have very meritoriously looked after and brought up your nephew over a period of years, however, on this particular occasion you failed him," he said.

And while accepting there was some provocation, Justice Burns said the pair's conduct was only going to escalate the situation.

"Each of you attended at the scene of the offence expecting conflict and with a loaded firearm ... now that behaviour is quite outrageous, particularly when you're looking at a public street."

Jarron was sentenced to two years and six months imprisonment and placed on a good behaviour order. Justice Burns ordered him to complete 200 hours community service.

Joshua was sentenced to two years imprisonment and placed on a good behaviour order. He'll also have to complete 150 hours of community service.