It's only the second time Cowboy Action Shooting has been part of the games, Innes said, and the first was back in the 1970s.
He's been shooting every Sunday for seven years with his Alexandra Pistol Club and said members must shoot at least 12 times a year to keep their licence to own pistols.
He's glad for this week's competition, because Covid-19 is preventing travel to the United States. He's planning how it can be added to the 2022 Masters Games in Dunedin.
There are only four clubs in New Zealand that can hold a big event, he said, and Whanganui's is one of them.
The competition is a chance for the public to see "the healthy side of shooting as a sport". Most members have been affected by the New Zealand gun laws that arose after the mosque shootings of 2019.
"There was a good turnout and a lot of interest yesterday," Innes said.
The rules of the sport come from the US. There are annual North and South Island competitions, and annual nationals held in alternate islands.
Some people just like dressing up and shooting the guns.
The weapons were all designed more than 100 years ago, and competitors wear 1800s and 1900s cowboy dress - a rule brought in to attract more women to the sport. If they enter a "Hollywood" category, they can add bling.
There are 15 female competitors in Whanganui.
The guns shoot real bullets. Safety is paramount, Innes said. Everyone shooting must wear glasses, to protect from potential bounce back from targets, and ear protection against the noise.
He asked the shooters to look after older members, sweltering in their cowboy gear, and make sure they drink plenty of water.
"Range officers are in control of the shooter, from the minute they stand at the line to the minute they leave. We are there to keep them safe, and the crowd safe."
Mateship is a huge part of the sport's appeal, Innes said.
"We consider this our mental health. We come here and we see our mates, we have a big hooha. We have a few beers after shooting. We are a pretty close community.
"Because these are restricted weapons, we keep a sharp look out if anyone's not right."