Here are some photos of a Big Shot or Rogue Sidewinder (
See Swamp Fox's folding slingshot) sling shot pull and hold trigger system that I cobbled together. I've been using it for a while and it's held up well.
It combines a Wichard snap release from Sherrill with a nylon sleeve and Klemheist hitch pull and hold. The big snap attached to the sleeve allows the pear screw_link_ on the Wichard to be easily hooked up to the pulldown. The orange cord is the trigger release. The pulldown can be used on a sectioned or single length pole.
Once the Wichard is hooked up to the sleeve it can be pushed down the full length of an 8-foot slingshot pole with the assist of the arms and body weight pushing down from above. This means a person of less than average or average strength can tension a Big Shot well enough for very high throws.
Pulldown and release on Rogue Sidewinder, view larger photos

-moss