Improvements--some small, others revolutionary--fell into place one after the other, and season after season saw improved loadings. By the 1980s, the myth that it was "impossible to load an ounce of steel shot" had long since been disproved by the simple expedient of designing more spacious shot cups. This, however, was not as easy as it sounds, because the cup and wad are part of a combustion sequence that requires rigid balancing. Change one element and everything else changes, meaning different loads and even entirely new types of propellants had to be developed. But by then the ammo industry had the steel-shot bit in its teeth and was in full gallop.