As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PROPELLER RPM GAUGE INDICATED 300 RPM OVER REDLINE DURING FLIGHT. PILOT PERFORMED PRECAUTIONARY LANDING AT FIELD OTHER THAN PLANNED. FURTHER INVESTIGATION OF ENGINE AND SYSTEM: NOR TORQUE FLUCTUATUON, NO ITT FLUCTUATION, NO N FLUCTUATION, INDICATOR FAILURE ONLY. REPLACED INDICATOR. OPS CHECKED GOOD.