Hi Gary, Welcome to Birdforum! I was wondering if you read any of the Regal 100 threads? 600 yds. is that to identify, see bullet holes etc. ? Also have you read" Premium Spotting Scopes in Review" on the 6mm BR site?
Bullet holes are exactly what I have in mind. I have a Celestron C90 and a C135 but they just are not sharp. I wonder if the fault is in the eyepieces? What would you recommend in an eyepiece for either if you feel they have the capability of resolution at that distance. Is it possible without ED glass?