Alright, the Drozd wasn't designed for steel bb's, it was designed to shoot 4.5mm/.177 lead balls, and it even says not to shoot steel in the instructions. They did come with a package of steel bb's, but that was EA's idea, not the factory's. The proof is that it has a rifled barrel, and no magnet, bb guns always have a magnet, and smooth bore barrels. So if you shoot steel, aside from other problems, it's really inaccurate, as steel bb's are smaller than lead balls, since they would really mess up the rifling in the barrel, steel on steel is a bad idea. Some people upgrade to tighter smootbore barrels to help, but since there is no way to impart a spin on a steel bb, there is only so much you can do. If you shoot lead, the things are deadly accurate, as the lead balls bite the rifling, so they spin. I can put bursts into an area the size of a nickel at 30 feet with lead. But lead balls this exact size are hard to come by, and expensive if you do. When I shoot steel, about 20 feet out, they just go wild in all directions, almost like they hit an invisible barrier. I knew a guy who was a minor league baseball pitcher, and he could throw a "knuckleball" that could do that somehow, and change direction and speed at the last moment, throwing off most batters, and that's how that worked, he put next to no spin on it by knuckling the grip, it was impressive to see him do (once he had a few beers in him, anyway), and it helped me (years later) to understand why the bb's do that at a certain distance, even when they don't hit anything, they still turn a corner in a random direction.
There is also the issue that the alignment isn't quite right in the mag head, so the bb's don't go straight into the barrel, which will erode the barrel pretty bad if you shoot steel at speed. We usually correct that, and the tendency for steel to "dribble" by sticking a tiny magnet in the head.