"It was a challenge but I swapped about six months ago to archery and poured everything I had into the sport and put in the hours with a good coach from the Shore Archery Club."
He began to nail the basics and managed to win a bronze medal in the novice section at the games.
"There were some better archers than me there competing but they shot fast and didn't have the same consistency. I really just practised the basics hard."
The experience for Mr Matairangi was much more than just competing and winning a bronze medal.
He said it was about being a spectator and meeting inspirational servicemen, who had to overcome many challenges to get to the games.
"On the Monday there was a quad amputee running 1500 metres with blades on and he came last but got a standing ovation. I couldn't believe what he managed to do.
"The Invictus Games was not about getting medals as for some it was a victory getting to the start line. Being able bodied my respect for what some of the others could do was next to none."
He said hearing their stories and seeing them perform was inspiring.
"On a basic level everyone there was the same, broken but not beaten, so we could all relate to one another. It was pretty amazing."
Mr Matairangi also rubbed shoulders with Prince Harry, who he described as a "bloody legend".
He said he was a genuine guy who found time for everyone and would give up his time to speak to those competing and their families.
"He would just pop out of nowhere and, for a busy man, he genuinely cared about what people did and where they came from."
Since getting back from the games Mr Matairangi hoped to take archery a step further and compete for New Zealand in the Olympics.
He said the games taught him to set higher goals for himself.
"This is an aspiration of mine and if I get there or not that's fine but wanting to strive for the goal is what drives me. It's not about the medals but it's about striving for the goal and improvement and that's what I got from the games."
Mr Matairangi was one of 24 athletes from New Zealand, who competed in the 10-day event. The next games will be held in Sydney next October.