I have a buddy who has a range on his property that he lets people come shoot on. But he has a range release that he has everyone sign every year releasing him from being reliable if you shoot yourself. That's what I would do first. Even though most of the people here probably wouldn't try to sue you, their insurance company sure would.
We've had 50+ family members shooting at the house many times, but I don't think I could open it to public. Not to be greedy, but I actually get nervous around other people I don't know with guns ... that's part of why I don't go to public ranges very often. Neal
I would definitely have a release form of some sort if you are going to have a bunch of strangers there that your friends invite. That seems like a lotta heartburn as there is always one idiot in the group.