falcon

You probably already know this but I'll list it anyway...

The SST's come with a HPH-12 sabot - I am surprised you even get that one down you Omega or Encore...

The TC ShockWaves (same bullet) comes with either the HPH-24 Sabot (black) or the "easy glide" the easy glide is the thinnest sabot the 24 being sligthly thicker.

The Hornady "low drag" is a HPH-3p-EZ and is a thin sabot built along the deminsions of the easy glide....

The "crush rib" is the thinnest sabot on the market - or it can be if you crush the ribs down tightly.

From your description - I would guess the "crush rib" is to loose in your bore(s) the "low drag" "easy glide" & if you have tried the 3p - they are slighly tighter than than the low grag therefor giving you a more acceptible group, but the sabot you need might be either the HPH-24 or Harvester regular sabots. I shoot these from my Omega and I can get the second, & third down with moderate pressure - the fourth is usually a struggle without patching - if I damp patch between shots all will go down correctly.

Just sharing some thoughts... but again it is probably old information to you....