The custom mouldable plugs are the only way to go in your situation. Personally, I use plugs and muffs! My hearing is pretty bad after a lifetime of shooting, rock 'n roll and jet engines and at this point I don't intend to let it get any worse. I use some very comfortable plugs that are, unfortunately, no longer made. They are kind of like miniature tampons (without the string, thank you!) and have a NRR of 29. Any of the other plug types drive me nuts so when these are gone, it will be the custom plugs for me... plus my muffs. My advice is don't shoot anything, anytime, without ear protection. I like my Dillon electronic muffs for hunting.
Cheers,
crkckr