firing mechanism vs gunlock

firing mechanism and gunlock both are nouns.

Word	Noun	Adjective	Verb	Adverb
firing mechanism	Yes	No	No	No
gunlock	Yes	No	No	No

As nouns, firing mechanism and gunlock are synonyms defined as:

firing mechanism and gunlock: the action that ignites the charge in a firearm

firing mechanism (noun)	gunlock (noun)
the action that ignites the charge in a firearm	the action that ignites the charge in a firearm