: a more powerful version of something His first argument didn't work, so he changed his approach and brought out the heavy artillery.

What was heavy artillery used for?

Artillery (heavy guns) played a big part in the battlefields of World War I. A bombardment that was aimed well could destroy enemy trenches, and knock out artillery batteries (groups of guns) and communication lines. It could also help break up an attack by infantry (soldiers on foot).

What is heavy artillery fire?

Definition of barrage

the heavy fire of artillery to saturate an area rather than hit a specific target; "they laid down a barrage in front of the advancing troops"; "the shelling went on for hours without pausing"