The home kill butcher who accidentally shot his teenage assistant has been a competitive shooter since he was a teenager and still hopes to compete at the Rio de Janeiro Olympics.

On Monday, Bruce Scott pleaded guilty in the Waitakere District Court to careless use of a firearm after he shot Simon Alex, 18, on a Kumeu farm on March 15 as they prepared to slaughter two cows.

The matter is scheduled to go to a disputed facts hearing in November 14 - before sentencing - as Scott wants a discharge without conviction so he can keep his shooting dreams alive.

Scott, 46, has been on the trigger end of the rifle since he was a youngster and has represented New Zealand at a competitive level since he was 16.

He is also an ace archer and won two world titles for New Zealand, one of which was in Australia at the World Archery Championships in 2005.

"I've been wanting to compete for New Zealand at the Olympics since I was a kid. I tried to make the NZ Olympic team for rifle shooting at Seoul, and I narrowly missed out on selection there," Scott said yesterday.

Alex medically died twice after the powerful .303 bullet ripped into his chest following the shooting and had to undergo a series of dramatic treatments to survive.

But despite this, he's back working at Scott's side and has written an affidavit in support of him.

President of the New Zealand Clay Target Association, Keith Livingstone, and Scott's coach have also done the same.

"Both of them stressed that if I did have a conviction it would almost certainly curtail my Olympic dream to be able to compete for New Zealand," Scott said.

At Monday's hearing, Judge Heemi Taumaunu said the law required a person in Scott's position to know and check where their assistant was before firing in circumstances where there was a risk they could be hit by a bullet.

"Mr Scott fired in [Alex's] general direction - and that's it in a nutshell. He did not clearly identify where the victim was when he took the shot."

During the shooting, Alex lay on his stomach 30m away, over a fence and beside a shed.

The bullet ripped through his main arteries running from his heart to his left arm, pierced a rib and struck his lungs, causing them to collapse.

The bullet came to a stop in his chest around 20cm below the entry wound.

His injuries were so severe he needed 20 litres of blood - the body typically contains five.

Surgeon Li Hsee said Alex was the most critically injured patient he has seen and gave him a five per cent chance of survival - odds the teenager beat in what rescuers said was a true miracle

Follow @AucklandNowNZ

- © Fairfax NZ News