Can you transfer from Navy Reserve to Active Duty?

Navy and Air Force,, actually all 4 branches (+ Coast Guard) are overmanned right now, but it's not impossible to get in. Simply because the nature of the organization, they keep recruiting people and dumping people at the same time. Although Navy is overmanned, it seems like Equipment Operator (EO) and Master at Arms (MA) are always hiring, or certain ratings may have openings at a certain time for some weird reasons.