You might be a gunline if...
...you roll more dice than a wood elf in the shooting phase.
You might be a gunline if...
...you run out of targets to shoot at.
You might be a gunline if...
...Chosen of Khorne Chaos Knights survive your barrage, turn your flank, and mow down your unarmored handgunners like grass under a thresher...
...you just might be a gunline.