bull's eye vs bell ringer

bull's eye and bell ringer both are nouns.

Word	Noun	Adjective	Verb	Adverb
bull's eye	Yes	No	No	No
bell ringer	Yes	No	No	No

As nouns, bull's eye and bell ringer are synonyms defined as:

bull's eye and bell ringer: something that exactly succeeds in achieving its goal

Other synonyms of bull's eye include home run, mark.

bull's eye (noun)	bell ringer (noun)
in target shooting: a score made by hitting the center of the target	something that exactly succeeds in achieving its goal
something that exactly succeeds in achieving its goal	someone who plays musical handbells
the center of a target	a person who rings church bells (as for summoning the congregation)