2/X Release mechanism for a slingshot gun

Partially finished. Gravity simulates the rubber here. The trigger mechanism holds onto the release mechanism. The release mechanism is an L-shaped piece of wood. There is two of them, and they are spaced just far enough apart to allow the pouch to be in between the the marble unable to pass through the gap. The L-shaped thing is under tension from the rubber, but is held back by the trigger mechanism. When the trigger is pulled, the hook is pushed backwards, and this releases L-shaped part so it can let go of the marble