gun barrel vs tubing

gun barrel and tubing both are nouns.

Word	Noun	Adjective	Verb	Adverb
gun barrel	Yes	No	No	No
tubing	Yes	No	No	No

As nouns, tubing is a hypernym of gun barrel; that is, tubing is a word with a broader meaning than gun barrel:

gun barrel: a tube through which a bullet travels when a gun is fired
tubing: conduit consisting of a long hollow object (usually cylindrical) used to hold and conduct objects or liquids or gases

Other hypernyms of gun barrel include tube.

gun barrel (noun)	tubing (noun)
a tube through which a bullet travels when a gun is fired	conduit consisting of a long hollow object (usually cylindrical) used to hold and conduct objects or liquids or gases