I'm not into scanning, but when you get the Besler set up expose the contact sheet for a long enough time for the film rebate edges to be black. This will indicate wether or not proper in camera exposure and subsequent film development was given.
Your problem may not be over development, but not enough exposure of the contact sheet. Follow the manufacturer's time and temp for the film and developer will get you in the ball park. Do not over agitate the film and developer.
If the shadows in your negative are clear, underexposure is likely the problem. If you have shadow detail, but low contrast, underdevelopment is indicated. Many of us routinely give B&W film a stop or so more exposure than the maker recommends. Any development chart is only a beginning, to be adjusted to the photographer's personal preferences.
What type film roll did you use? Not what type film but the roll/spindle/carrier that you placed in the developing tank? Guess the proper name is developing reel?
The manual, stainless steel type or the plastic, self-feeding type?
In this case, that should not affect the development. It is easier to mess up the loading with metal reels. The most common error is two layers of film coming in contact with each other. I would like to see a non film scanner contact sheet, because that is the best way to evaluate the negs. Take a test strip and expose it for the time that just shows the sprocket holes. Disregard the pictures when judging exposure for a contact sheet.