McSweeney (25), a personal trainer at Les Mills gymnasium, has played golf and cricket and represented Wellington at junior tennis.
Athletics is his latest and most successful sport and he will make his international debut at Christchurch in the CF 44 below-the-knee javelin in January.
He is one of a nine-strong New Zealand team named for the world paralympics athletics championships.
The team is headed by Commonwealth Games silver medallist Jessica Hamill (Southland) and Beijing 2008 Paralympic Games 200m silver medallist Kate Horan (Wellington).
It also includes 2004 Athens Paralympic gold medal-winning middle distance runner Tim Prendergast, now based in London.
Hamill spent time training in Dunedin with coach Raylene Bates before the Commonwealth Games.
McSweeney had his first javelin competition at Christchurch in January.
Less than a year later, he will be competing internationally.
"I'm excited," he said. "It's a milestone for me."
McSweeney has taken a positive approach to life and intends taking it into the world championships.
"It's all about ability. Disability doesn't come into it," he said.
"Sport is the challenge I've chosen to pursue."
He has had injuries and ongoing pain as he has learnt the rudiments of javelin throwing.
"It's a difficult technique to master. There is still a gap from where I am to where I want to be."
His confidence has improved since he shifted from Wellington to Dunedin in November to train with Bates, the coach of the AWD athletes at the Commonwealth Games in New Delhi.
McSweeney has two carbon-fibre blades - one for daily use, with a heel, and one for athletics, without a heel.
He had to face regular problems growing up as he adjusted to a new artificial leg as he kept growing.
"I have always tried to keep positive and be grateful for the things I do have, " he said.
One of his biggest challenges will come when he competes at QE2 Park at Christchurch in the world paralympics athletics championships.
His best javelin throw is 38.80m.
New Zealand Paralympics team
Joe Flavell (Auckland, shot put), Sunil Fernandez-Ritchie (Waikato, 1500m), Jessica Hamill (Southland, javelin and shot put), Katie Horan (Wellington, 100m and 200m), Matthew Lack (Bay of Plenty, wheelchair 400m, 800m and 1500m), Rory McSweeney (Otago, javelin), Tim Prendergast (Wellington, 800m and 1500m), Holly Robinson (West Coast, javelin and shot put), Chelsea Seagar (Auckland, 100m, 200m and long jump).
