crapshoot vs crap shooting

crapshoot and crap shooting both are nouns.

Word	Noun	Adjective	Verb	Adverb
crapshoot	Yes	No	No	No
crap shooting	Yes	No	No	No

As nouns, crapshoot and crap shooting are synonyms defined as:

Other synonyms of crapshoot include crap game.

crapshoot (noun)	crap shooting (noun)
playing craps	playing craps
a risky and uncertain venture