I don't know if there's a "magic number," but I prefer wide forks, just because that's what I'm used to with factory metal slingshots. My catties from Trumark, Daisy and Crosman vary between 3.5" and 4" between prongs. One of my natural Y forks I made only has about 2" between the tips of the prongs, and if don't use the "flip" style of shooting (which I'm still not very good at) I hit the fork regularly.
