Normally, you don't put anything in the scope rings, and don't do them up too tightly, or you may mark, or even crush the tube. I use the long arm of the allen key in the bolt, and the short arm to tighten. If you have a spinger, then pehaps tighten a bit more, say 1/8th of a turn with the long arm. The main bolts on the dovetail clamps can be done up fairly tightly.
Zero your scope at 15 yards. If it is shooting low, and you run out of elevation adjustment, (top turret,) you will need to put some cut pieces of negative, or silver foil under the tube in the rear mount. Three thicknesses is the recommended maximum, if this doesn't work, you may need adjustable mounts, such as "BSquare." For a .177, the scope will now be roughly zeroed at 35 yards as well, but you may need some fine tuning.
Good Luck..!
Gus
The ox is slow, but the earth is patient.