Danger Boy - S2-E16
Trivia: When Cory is despondently leaving Chubby's, he passes by a rack of comic books. According to Rider Strong, producer Michael Jacobs is a huge fan of comics and freaked out on the props department that the comics were outdated and not restocked with more current issues on episode to episode basis. (00:08:50)
Answer: These are dragon's breath shotgun shells. The shells are filled with magnesium pellets and ignite when fired. The film seems to exaggerate the stopping power, making it seem almost like an explosive round rather than incendiary. These are not the same rounds that we see the men carving into. Carving grooves into a bullet is done so the bullet expands upon impact and causes more damage similar to a hollow-point round, though the effectiveness of this method is debated.
BaconIsMyBFF