It seems that you are limiting your gold range too much if you start at VDI 22 and stop at 30. Again, 42-47 VDI is a pretty small window as well. I think Rob pretty well hit it on the head with most lost gold rings probably VDI at less than +22.............95%, I don't know about that, but I would safely say over half of the gold rings lost would be small ones for many reasons. Nancy has found gold rings as low as VDI 8, I think, and I have found lunker class rings as high as VDI 65 in the ground. Out of the ground, it VDI'd lower, in the low 50's I believe. Rings will vary in tone depending on how it is sitting in the ground and how rough the surface of the ring is. Class rings tend to sound very trashy because of all of the different angles to scatter the signal. Wedding bands on the other hand usually give a nice smooth "round" sound.
There is an old adage in this hobby that says it all. To find it all, you must dig it all. It couldn't be more true for gold ring hunting.