The hired sniper convicted of murdering a bikie leader at a drag racing event with a long-range shot can be identified after a gag order was lifted.

Benjamin Luke Johnston gunned down Nick Martin at Perth Motorplex in December 2020 as the then-Rebels chief sat with his wife and associates in the spectator area.

The former soldier's name was previously suppressed by the courts for his safety after he agreed to give evidence against Comancheros bikie David James Pye, who has also been convicted of Martin's murder.

Johnston, 43, successfully applied to the Supreme Court on Friday for the order to be lifted, saying it was negatively impacting his life in prison.

Mail was not reaching him and people were having difficulty booking prison visits to see him, Justice Joseph McGrath said as he delivered his reasons for lifting the gag order.

The prison population knows who Johnston is, the court heard, and he has no fears for his safety in protective custody.

He also wants to enrol in a university course while he is serving his 20-year sentence and the suppression order on his identity was preventing this, Justice McGrath said.

The former army reservist who was an artillery gunner carried out extensive research for his sniper attack, including flying a drone over Martin's home to assess the security and approaching within 10m of him at the racetrack.

On another night, he sneaked into the venue and moved a safety ramp which interfered with the line of sight between Martin's usual seat and his intended shooting position.

The gunman, who said he worked for BHP at one time, tested his high-powered rifle by firing 200 rounds at a small target in isolated bushland.

On the night of the killing, Johnston put on a camouflage suit and gloves, climbed through a hole in the fence and crawled to his position in a heavily vegetated area.

The assassin watched Martin through the scope of his rifle for about 10 to 15 minutes as he made adjustments based on wind speed calculations and other factors.

He fired a single shot from a .308-calibre rifle which struck Martin on the chest, causing him to exclaim: 'I've been shot'.

'Exactly 365 metres,' Johnston said during Pye's trial.

'His entourage of bikies were sitting around him to act as muscle protection.'

The bullet passed through the 51-year-old's back and struck his son-in-law Ricky Chapman in the left leg before lodging in his arm.

Martin died in hospital but his son-in-law survived.

About 2000 people were at the event and a five-year-old child was seated behind Martin.

Johnston would ordinarily have faced life imprisonment, but he will become eligible for parole after serving 18 years, after he received a substantial sentencing discount in exchange for his co-operation.

The trained marksman first met Pye via Instagram when he was working for a medical charity in Iraq, the court has previously heard.

After he returned to Australia, he allegedly visited Pye at his home in Perth's southern suburbs.

He said he asked Pye to supply him with the illegal drug MDMA, to which the bikie allegedly said he could get a kilogram.

'He was the dodgiest person I knew,' Johnston said during Pye's trial.

Pye later offered Johnston $150,000 to kill Martin, but he was ultimately paid $100,000.

Johnston was arrested weeks later, having been under police surveillance in relation to the Motorplex shooting.

Pye is scheduled for sentencing on May 13.

His lawyer Paul Holmes opposed Johnston's application, saying his client was likely to appeal his conviction and Johnston could testify if there's a retrial.