"But then there are plenty of gun folks who think no one should rock the boat because it might piss off the anti gun crowd/politicians and cause even more gun control." - Bikenut
Submissive gun rights advocates need to lose their submissiveness before we lose our 2A rights.
The easiest thing to do would be to do it yourself. That way, they would most easily get to the people you wanted. Otherwise, you leave it up to the people that are in charge after you die. I don't know if you have a will or a trust. Ideally, you should talk to people about what you want to have happen AND provide detailed instructions. IME, after someone dies, it isn't unusual to have all sorts of relatives come forward and talk about how uncle so-and-so promised this certain item to them.
Opinions and comments made by me on this forum should not be considered legal advice.
The NRA has a program that does just what you are asking. All my stuff is to go there, be auctioned, and the funds donated to programs I designated.
What about a university? I read recently that Hillsdale college has a very extensive set of shooting/outdoor programs.