With a mammoth personal best, a gold medal around his neck and a winner's smile it's fair to say he achieved his goal.

Months of travel and training paid off for Bathurst High School student Simmons, 17, when he claimed the boys under 18s javelin title in Perth on Sunday.

Simmons entered the tournament with a personal best of 58.29 metres but knew if he could get himself above the magical 60 barrier he'd in with a great shot of a podium finish.

"I was really shocked. I went out there with a goal of hitting that 60 metre mark. To better that twice was amazing. I did three new PBs in a row," Simmons said.

"I knew I could win no matter what everyone else throws, because it all comes down to what you can throw on the day, and after I threw that new PB with my first throw I thought 'I've got this covered'.

"Everything just went perfectly for me. I was coming in at the right speed and everything was on point."

That new best mark was 59.37m and it shot Simmons straight to the top of the leaderboard after the first round of throws.

Simmons fell short of that effort on his next attempt and a little bit of pressure was applied to the Bathurst competitor when fellow New South Welshman Will Irish (58.47m) and Victoria's Oliver Blackburn (58.09m) got themselves into the 58s.

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However, the big moment came on attempt number three where Simmons put down a 61.90m to once again better his previous best.

No-one would end up bettering that distance.

The top eight competitors were all given one more attempt, and the man at the top of the leaderboard decided the job wasn't done.

Simmons ended his event on a high by throwing a 62.34.

He finished clear of Queensland's Hendré Kirchner (60.88m) and Irish (60.65m).

"I sacrificed a lot of time with training and travelling," Simmons said.

"I trained from 9 to 12 on Sunday morning and I'd travel to Lithgow to train from 2 to 5. I've been going on for two years now with my coach Hayden Perry and it's been going well.

"A big thanks has to go to my mum and also to my coach for taking the time to come over and help me."

Simmons won't be eligible for another shot at the junior national level which means it's time for him to move on under 20s, which also comes with a 700 to 800 gram javelin weight increase.

"I've got a goal to hit a 69.50m next year for Junior Worlds qualification," Simmons said.

The gold medal for Simmons also came with an additional prize.

Courtesy of beating Perry's distance when he was in the same age group, Simmons' coach gave him his javelin to use in his qualification bid next year.

Simmons has several opportunities to qualify for worlds at both the NSW Country Championships in Dubbo in January and the Australian Athletics Championships at Homebush in March.

Reaching the required mark in either of those events would book Simmons a trip to Kenya for the IAAF World U20 Championships in July.