retarded blowback vs delayed blowback

retarded blowback and delayed blowback both are nouns.

Word	Noun	Adjective	Verb	Adverb
retarded blowback	Yes	No	No	No
delayed blowback	Yes	No	No	No

As nouns, retarded blowback and delayed blowback are synonyms defined as:

retarded blowback and delayed blowback: A type of firearms operating system which requires the bolt to overcome some initial resistance while not fully locked.

retarded blowback (noun)	delayed blowback (noun)
A type of firearms operating system which requires the bolt to overcome some initial resistance while not fully locked.	A type of firearms operating system which requires the bolt to overcome some initial resistance while not fully locked.