The bore and groove dimensions are both in the middle of the current CIP minimum specifications. But contrary to popular belief, these fimensions are rather uncritical. Instead, the chamber dimensions of a minimum I chamber may cause excessive pressure. As the S bullet is larger, the neck of a loaded cartridge is larger too. A S cartridge may barely slip into an I chamber, but without any space to expand and release the bullet on firing. Additionally the S bullet is sort of wedged into the barrel leade, without space to start moving.
So take an I cartridge and shoot it in the rifle. If an S bullet can be slipped in and out the fired case wit finger pressure, you may use S loads.