Most of that ammo is what I consider "Soldier of Fantasy". The flechette rounds were developed for folks pulling guard duty on aircraft. "Yes sir, we shot the sapper that was trying to destroy the airplane. However, our rifle fire destroyed 4 other aircraft."
Not enough mass to tear up airplanes at distance. Basically little steel arrows. When fired from a 105 howitzer, REALLY impressive- but it held 8,000 of those little darts.
What we have here is... failure- to communicate.