OK, Thank you very much for such a complete answer, I get it now.
Right now,too many projects on the bench at one time. The mod 16 is using a .308 barrel, so the short bottom plastic will be fine, and full pillars are the way to go, that top picture convinced me, Some days I'm slow, other days, not that good...

The other project is an Edge, now in .308, (that barrel will be cut to 17 inches, braked and used on my Striker) soon to be 25-'06. What I'd really like is a pilaster style super sniper stock for it, but that also seems to be eluding me at present... I have a Choate machine stock on a Rem 700, heavy barrel varminter and I absolutely love it. Any suggestions on that one? Thanks again, Paul in da swamp.