straight off vs like a shot

straight off and like a shot both are adverbs.

Word	Noun	Adjective	Verb	Adverb
straight off	No	No	No	Yes
like a shot	No	No	No	Yes

As adverbs, straight off and like a shot are synonyms defined as:

straight off and like a shot: without delay or hesitation; with no time intervening

Other synonyms of straight off include at once, directly, forthwith, immediately, instantly, now, right away, straightaway.

straight off (adverb)	like a shot (adverb)
without delay or hesitation; with no time intervening	without delay or hesitation; with no time intervening