order arms vs manual of arms

order arms and manual of arms both are nouns.

Word	Noun	Adjective	Verb	Adverb
order arms	Yes	No	No	No
manual of arms	Yes	No	No	No

order arms (noun)	manual of arms (noun)
a position in the manual of arms; the rifle is held vertically on the right side with the butt on the ground; often used as a command	(military) a prescribed drill in handling a rifle