John 71 --
Some "jumping" that you might be seeing, is possibly due to multiple targets in the ground, being seen (and identified) by the machine very rapidly.
While on deeper targets the ID may not "lock" onto ONE number, it's not leaving much doubt that there's something you need to "check out" down there, on targets that you should be digging. Even at max depth, it's giving you "diggable" information. What is "bouncy" to one person is "accurate" to another (like myself), as long as the bounces are not too broad, and all in the right "range" (i.e. implying the correct type of target). If I hit a 9" deep penny, and it's bouncing 22, 24, 25, 23, 25 22, 26, 23, 24, 24, to me that's EXCELLENT ID on a deep penny. Others may call that "bad," and "bouncy," so it's somewhat subjective.
I can say, though, that if you think in "ranges" -- like low 20s = zinc or Indian, mid 20s = clad dime or penny, mid to upper 20s = silver dime or clad quarter, upper 20s to low 30s = silver quarter...stuff like that....and then, if your expectations are for a 1-2 number "lock" on these targets at under 6" and then a few numbers of "variation" on deeper ones, but still in the correct "range," I think you will be quite pleased.
Steve