Bruce Bowman

Can't get them here, either (central Indiana). If I want yellow grapefruit juice, I have to buy it bottled.

5/12 of an oz of lime juice? Peculiar.

I think I'll go with a tablespoon. Seems to me there's more of a difference from lime-to-lime than 1/12th of an oz would make.

I used Don Q and faccia brutto and bumped things up x1.5 so the measurements come out easier (as it probably should be).
Wow. Prepare to have your socks knocked off. It's really strong, both in alcohol and flavor. This is a sipper, not a gulper. Could you fuel a rocket with it? I wouldn't be surprised.
Very herbal/spicy, the lime and rum take a back seat here. Very complex, it reminds me of a Last Word, but more in your face. The Falernum contributes sweetness and pleasant notes of nutmeg/cloves. Very warming on a cold winter's night.
The Nuclear Daiquiri bears little resemblance to a regular Daiquiri, Hemingway or otherwise. But it's still a 4-star beverage, and a great way to use up these less-mainstream components. Believe me, it'll kick your hind end, too. Bottoms up!

Sour, yellow grapefruit juice is the key here. It would probably go out of balance with ruby red.