You can't be serious!!
Absolutely! Have you ever watched a hunting slingbow in action? Since writing my response, I chrono'd one, and with an Easton 2114 AL 30" arrow with a 100 gr head. The avg for 3 shots was 237fps! My old 50lb recurve avg 199fps, and the old Bear compound from the early 90's came in at 224fps!
Slingbows, with heavy tubes, can be impressive, and since so few have any experience with a true hunting slingbow, it is often met with skepticism. Very similar to when I began bow hunting decades ago and people laughed at the idea of taking whitetails with a wooden recurve and "stick arrows" made of cedar. Someone forgot to tell the natives it could not be done.