Capt Morgan: Do you own a Machine shop or something? You do nice work.
Also another Dane worthy of note is this guy.
https://www.youtube.com/watch?v=DyzYDip9JTM He goes by Torsten on Youtube and shoots slingshots using the Butterfly or Albatross method. You will note in this video showing his technique that the velocity he is getting is 141.7 mps which converts to roughly 465 fps! Also note the size of the target box he is shooting at? Somewhere there is a video of him shooting at beer can bottoms at 60 yards! I think he uses 8 MM or 5/16" steel balls.
With accuracy and velocity like that he is equal to, or better than most of our airguns. Something to think about?
And if you think you are too old or feeble to shoot a sling shot or can't learn how to do it then you really need to rethink this. It costs very little to get into this sport and it is very rewarding and it ain't that hard to do, and you've got plenty of time to do it right now.
Lets actually accomplish something useful during our time in the box!
Randy