I've been playing around with this on my Morrison this last week. I use calf hair from Black Widow on the shelf and the plunger in the bottom hole. I initially set it so the tip of the arrow was just off center line. Everything was showing weak so I put a piece of toothpick inside the plunger so there is no springy effect.
After some minor adjustments, I have one arrow setup with perfect flight to 32 yards, both bare shaft and fetched, 525gr set up, would work for deer but I am hesitant for elk. It's a beautiful thing when you can put the bare shaft with the fletched shaft in a 1 1/2" spot at that distance.
Was working on a 600gr setup today and I am real close, maybe close enough.