Dr Fallout
Centurion
What do you mean by researching it? It was part of the research that went into the old Star Wars anti-ICBM program, it's part of the research into real-world electromagnetic guns and hyper-velocity missiles, and it's part of astrophysics research in the form of meteorites. Kinetic warheads have also been part of sci-fi for awhile; the most recent that I know of is Schlock Mercenary's c-sabots.
It was researched in the real world, yes but last time I checked Fallout was not the real world, they had different technology there due to different research, hence the idea that just because we researched something doesn't mean they did.