[ttldomination]

75 pounds is A LOT. We'd have roughly 30-40 (50 pounds at our strongest) and we can get a decent 30-25 feet. It really also depends on how far away your point of rotation is sitting, generally farther is better.

If you don't mind, post a picture/video of your setup, and that'd be better for us to help out.

Also, are you manually releasing it or is there a mechanism involved? Depending on what you're doing, you could have a mechanism that's burning too much energy in the release.

Try messing with the angle of incidence and size of kicker and see what you get. I would recommend messing around with wood prototypes because they are much easier to change/modify than metal/80-20.