Bone, first set your OAL to function properly from the mag. It must be a bit shorter then the internal dimension so the cartridge has room to move.
Then you tune your load to suit that OAL. As long as the ammo is made true, there is little reason to have the bullet on or jammed into the lands for best accuracy. This applies to most VLD's as well.
I find that having it 10thou or more OFF the lands works just fine and ensures extraction doesn't cause any issues. This is really important for a hunting rifle.
The one thing you should check is to ensure the bullet fully engraves into the lands BEFORE it leaves the case neck. If it engraves, you can tune that load for very good accuracy. If there is a jump, no matter how small, the barrel will be MOA at the best.
Of the many Shilens sold, there have been no issues with the chambers that are cut and the reports of accuracy have been excellent.
Jerry