[Bull Snipe]

Another problem for Alexander, Hunt had ordered Union guns to stop returning fire. Not to conserve ammunition, but to let the Confederates think that the massive bombardment had been effective and launch the infantry assault.
50% of the Confederate killed and wounded during Pickett’s Charge were caused by Union Army artillery.

[nathanbedford]

" the greatest cannonade the North American Continent had ever witnessed as Alexander peered through his glasses, trying to fathom if the Rebel bombardment had created the necessary conditions for their infantry to advance. (Emphasis supplied)

One wonders whether the Confederates had sufficient ammunition and one presumes that the Yankees had ammunition aplenty. One wonders whether the practicalities of horsepower logistics had anything to do with the, presumably, disproportionate artillery available to the contending sides.