There were many clubs in the district, with quite a few formed by returned servicemen.
"A lot of these clubs started between the first and second world wars," says Gordon.
"The original rifles were Lee Enfields with a sleeve," says Sid.
The Lee Enfields were .303 calibre and the sleeve in the barrel took them down to .22, the regulation calibre for target shooting and the standard today. Sid says clubs started in Britain after the Boer War to train marksmen.
"The first club in New Zealand started in 1920."
The association was formed to bring separate clubs together.
"Looking through the history, there were so many clubs organised in Whanganui — for instance, Imlay might have had a club, a lot of the businesses — and some of them were using our ranges to shoot on," says Raewyne.
Graeme says their research suggests there were 44 clubs in the district at one time. Apparently there were ranges everywhere, including somewhere at the railways, in woolstores and other places. Halls such as Upokongaro, Mangamahu and Westmere were used for ranges, with targets set up under the stage.
"Castlecliff's [range] was under one of the wharves," says Gordon.
There was a tin shed there with so many holes in the walls it was lit with natural light, so they say.
Raewyne says she shot there for a season in 1969 when the RSA range was having work done on it. Sid says competitions were shot in the Castlecliff tin shed with the targets under the wharf.
"The opening competition comprised Hairdressers vs 61 Cadets, P&T vs Imlay, Chronicle vs Castlecliff, RSMRC vs 10 Cadets," says Graeme.
Sid, who took up shooting in 1966, was one of the volunteers who built the Okoia Range, which was finished and opened in 1975. He says there was a lot of fundraising involved, including cutting firewood and shovelling sheep manure.
To raise extra money, the finished hall was used to store wool. So the floor surface wouldn't be spoiled by lanolin, the heart matai floor was dismantled and all the floorboards tipped upside down. When the wool storage was no longer needed, the boards were replaced right way up and no trace of the wool could be seen.
Before the hall and range were built, competitions were shot at the Municipal Range which is where the Whanganui District Council dog pound now stands. The original Westmere Range was on the site of Grange Transport. The range was destroyed by fire in the late 1970s, taking rifles, records and all with it. Some trophies survived.
Sid started his shooting at Upokongaro, where he was for 34 years. When the club finished he was president.
"It was a big club in its day. I then went to Whangaehu. Then I went to Westmere and became president on the very first day."
The association record books are filled with interesting episodes and comments, including one entry where a shortage of ammunition was mentioned.
"They used a five shot target, but only shot two or three and averaged it," says Graeme.
He says even the mayor got involved in the association in the 1940s.
Past and present members wishing to be a part of the centenary event can contact Paul Turner.
Email him at paul.turner @tsw.net.nz, or ring or text Paul on 027 2928787. If you are in touch with past members of the club, please let them know. Registrations must be in by October 14.