powder store vs powder magazine

powder store and powder magazine both are nouns.

Word	Noun	Adjective	Verb	Adverb
powder store	Yes	No	No	No
powder magazine	Yes	No	No	No

As nouns, powder store and powder magazine are synonyms defined as:

powder store and powder magazine: a storehouse (as a compartment on a warship) where weapons and ammunition are stored

Other synonyms of powder store include magazine.

powder store (noun)	powder magazine (noun)
a storehouse (as a compartment on a warship) where weapons and ammunition are stored	a storehouse (as a compartment on a warship) where weapons and ammunition are stored