Sir:
I think you might enjoy Jörg Sprave’s slingshot channel [1] on Youtube.com. His videos on his home made slingshot weapons, I mean he is something else!! he has a slingshot rifle with scope, a pump action repeating slingshot sort a rifle or pistol device, one that shoots machetes (yikes!!!) and a cannon slingshot, etc, etc, etc. I like the pump action [2] job. He even has a tutorial video on how he makes it. He shoots .50 caliber lead balls and I think it is comparable to a firearm for knock down power and penetration. he tests it on ballistics jell and it is impressive. I think you will enjoy looking at his videos, just type in Joerg Sprave in the search engine at Youtube.com and he has his own “Sling Shot Channel”. – Darrella