I think we're starting to get things narrowed down a bit.
I like the frisbee idea, but unfortunately I don't have anyone to throw it. I could do a frisbee hit, but it would pretty much be the aerial target with a different target.
In general I wouldn't mind trying a distance hit at some point. But at my current skill level I think it would just be continuous throwing until I got that one lucky shot. Not to imply that all my other good hits don't involve at least a small amount of luck.
You could be right about the pendulum being easy. I'll be able to set it up pretty quickly though. I have a swing set that's rarely used. I was going to take the swings down and hang up an old tire as a weight. I think I'm still going to give this a try and see how it is. If it is pretty easy, there will at least be another slinging video.
I like the ball rolling down the hill idea. Sort of like trying to hit something that's running at you. Like you, I'd also have to look around for a place to do this.
I think the small precise target might be our best option right now. I really like the candle idea. My concern with that is the wind will blow it out before the sling will. I don't have an indoor area for slinging. Maybe the nail is our best choice for something fairly easy to set up. What kind of distance are you thinking?