We're still cleaning up UXO on the seabeds from WWII and to a depth of four feet on Kaho'olawe, and you want to create yet another environmental hazard?!?
Waikiki's indoor shooting range exists almost exclusively for the hedonistic thrill of Japanese visitors who rarely get to touch, let alone shoot, a firearm. When our daughter was accepted to NROTC we sent her down there for a couple familiarization firings. On her second trip she thought she was pretty hot stuff with a .22 until the regular next to her started shooting his .357 Magnum.
They actually use a leash on the muzzles of the revolvers to ensure that the customer keeps them pointed downrange.