Green’s Dictionary of Slang

A-bomb n.

[the supposedly ‘explosive’ effects]
(US drugs)

a combination of marijuana or hashish with opium, or another narcotic.

[US]R.R. Lingeman Drugs from A to Z (1970) 25: A-bomb [...] A mixture of marijuana and heroin smoked in a cigarette [...]. More preferred are the combinations opium and hashish.
[US]E.E. Landy Underground Dict. (1972).
[US]ONDCP Street Terms 1: A-bomb — Marijuana cigarette with heroin or opium.

In compounds

A-bomb juice (n.)

(US) illicitly distilled alcohol, ‘moonshine’.

E. & S. Deak Grande Dictionnaire d’Americanismes (5th edn).
[US](con. 1940s–60s) Décharné Straight from the Fridge Dad 1: A-Bomb juice Moonshine liquor.
[US]A. Mariello ‘Dirty Dictionaries’ on Weekly Dig [Internet] Last night we went to my boy’s cid pad and got completely giffed on A-bomb juice. We were so activated we barely noticed our friend Al K. Hall slip through the front door.