In Chain of Command, artillery does not appear on the table. The game, after all, represents the sharp end of the stick where the infantry grunts are quite face-to-face. Artillery, and even medium mortars, have no place in such close quarters except as objective pieces. In-game off-board artillery represents medium mortar batteries at company or battalion level. CoC does, however, provide a gamer the option for using a larger artillery or air strike pre-game barrage that can potentially disrupt the enemy's ability to move forces into the battle-zone (tabletop). I had a thought to model some artillery vignettes to remind players of the pre-game barrage (it lasts the entirety of the first turn). And I'm finding that vignettes add some much needed colour to a WWII tabletop battlefield. I contracted out to Captain Dan at Red Over Blue (as part of our Lend Lease program) for the pieces below and with his usual skill he has rendered some lovely pieces and figures.
This is the Warlord Games Sig33 105mm howitzer with crew, comfortably ensconced behind scratch-built sandbags (although I've just noticed that the epaulettes are painted with white piping rather than the red of the artillery).
And for the Brits, the Warlord Games BEF 25lb gun with limber (I'm fully aware that the limber would probably not be so close to the gun but I claim artistic licence and lack of space).