I seat the bullets as far off the lands as necessary to make the rifle shoot well, or to the length of the magazine, whichever is shorter. Seating depth is another controllable factor when handloading for accuracy and can make a difference, but loading very close to the lands doesn't always yield better accuracy. Also, if you do seat them very close to the rifling, make sure you back the charge down at 5-10% and work up slowly. Pressure signs can come on pretty suddenly when the bullet doesn't have far to move before engaging the rifling.

I generally seat my bullets to the recommended COL in the load manual for the initial load workup. Once I find a powder charge that the shows promise, I will then load up another batch with different seating depths to see if I can shrink the groups more.

Mike