I left in 1997 so it has been a while. If you get a contact from the Parker ranch on the Big Island you can get so LR shooting in. Also a lot of good hunting all sorts of exotic species.
On Oahu if you can get someone in the Military they have some good ranges on the Army Base and Marine base in Kaneohe.
The Military also has some of the BEST Golf Courses in the world on Oahu.
There was a Public Range on the East side of the Island by the "Blow Hole" and there are some Private Ranches NW of Kaneohe that has yardage.
BUT that was 26 years ago.