Todays glass filled props are abrasive in nature and will indeed dull a lower grade tool steel reamer.

In machining glass filled materials such as G2 or Nylatron it is always advised to use carbide tooling as even the best
quality high speed cutters wear out rapidly due to the abrasive nature of these materials.

After 4 years and probably many props it is likely that your reamer has lost it's edge. Some times stoning the edge without
rounding it will help although it may reduce the diameter slightly.

Happy flying, Oscar