There shouldnt be any difference between the reserves and active duty ranks.
This from when he went through basic training but hadnt gone through ocs yet, remember you are an enlisted member before you accept a commision as an officer.
I am thinking of Custer as an example of the difference between regular Army rank and reserve (?) rank. He made major general during the civil war, but his regular Army commission never went over lieutenant colonel.
Actually, this was from when he went through OCS.
An OCS Officer Candidate holds an elisted rank equivalent to an E-5.
If he successfully completes OCS, he is commissioned as an O-1.
If he washes out of OCS, then he gets busted to E-1 and owes the Navy service in the enlisted ranks.