The spring tension of the cushion plunger determines how much the arrow is pressed against the plunger at the moment of release and how strongly it rebounds, directly affecting lateral arrow movement and flight stability.
If the spring is too soft, it absorbs more lateral impact, but excessive softness can delay the rebound and lead to unstable arrow flight. If the spring is too stiff, the arrow returns to center quickly, but insufficient shock absorption can increase left–right oscillation.
The appropriate spring tension varies depending on the arrow spine, bow poundage, and release style. In general, starting with a medium tension and making fine adjustments based on shooting results is the most stable approach.