shelling vs barrage fire

shelling and barrage fire both are nouns.

Word	Noun	Adjective	Verb	Adverb
shelling	Yes	No	No	No
barrage fire	Yes	No	No	No

As nouns, shelling and barrage fire are synonyms defined as:

shelling and barrage fire: the heavy fire of artillery to saturate an area rather than hit a specific target

Other synonyms of shelling include barrage, battery, bombardment.

shelling (noun)	barrage fire (noun)
the heavy fire of artillery to saturate an area rather than hit a specific target	the heavy fire of artillery to saturate an area rather than hit a specific target