I think it's largely a case of many of these clubs having an extremely poor online presence. The amount of experienced shooters that I run into with absolutely no knowledge of who the various local clubs operating are, let alone what discipline they shoot or a calendar.
Have a look at the S.P.A.R.C series. Well promoted online, very well attended by younger and new shooters, and they shoot at a ton of different locations.
Our local service rifle club is going the same way as the pistol clubs. All of the new members and young guys have been created by them shooting at another club with a service rifle member and being convinced to give it a go.
If your club is not coming up from a simple Google search and the times/dates/prices/photos/videos of club shoots and an explanation of your disipline are not clearly stated, don't expect young people to even know you exist.
Personally I fall into the price barrier category for pistol shooting. I do a lot of rifle shooting and simply can't afford adding pistol to this as well, even though I could make the time and would like to get into it.
Bookmarks