Ask the Expert: Can I Use Medium Strings on My Prewar Martin?
If the saddle has been lowered on your guitar in the last 80 years, and it likely has, then the torque on the top will have been reduced, too, which lowers the risk. This may be why you prefer the sound of the medium-gauge strings—they may put a load on the top that is comparable to what light-gauge strings would produce with a taller saddle.
