Reducing Ground Resistance to 5 Ohms, Think about it 5 Ohms? It can be reduced but not to an specific value.
You can lower a ground reading, but getting it to an exact value would be near impossible. There are too many variables at play.
NETA Reference for a Molded Case Breaker. Pole to Ground
Assuming molded case breaker is 600V then 100 Megohms - NETA ATS/MTS Table 100.1 Insulation Resistance Test Values Electrical Apparatus and Systems Other Than Rotating Machinery.
http://testguy.net/content/240-Insul...ce-Test-Values
Cable Bus Facts
Not sure what the question is.