Stockpiling those shells for a "huge burst" at the start of a battle is more than possible though. The main issue today, is such stockpiles are easily found by

Stockpiling those shells for a "huge burst" at the start of a battle is more than possible though. The main issue today, is such stockpiles are easily found by recon (satellites, airplanes, drones), and then blown up by enemy artillery / rocket artillery.