The gun in question is the 1903 carbine featured in the "Two Uncommon Mannlichers" post. The rear action screw will torque down very slightly past index, but the forward screw will go a bit beyond an eighth-turn past before it seems to snug up. Factory index is obvious because the screw heads are sculpted to the taper of the stock and/or corresponding steel hardware. For what it's worth, Mannlicher Schoenauers do have a steel bushing/ferrule surrounding the rear screw. Please keep commenting--I find all of this instructive!
Best,
Malcolm