[FMadera]

Yes, I'm saying you can have that. I'm also saying a volleyball bouncing off a sportcourt isn't going to bounce as high as a volleyball on a basketball court. A volleyball on basketball court A isn't going to bounce the same height as a volleyball on basketball court B. Not all balls have the same softness. A softer ball will compress more (and therefore, rebound less) than a harder ball. Every ball will react just a little more differently than the next one, so the bounce test doesn't fly.

The PSI rule is pretty clear. There is no other way to accurately measure it other than with a gauge of some sort. The rules don't specify how the ball should bounce, but they do specify how much air should be in them. Therefore, the gauge should be used to assess legality.