Needlegun

Theoretically, the advantages of a needlegun over conventional projectile firearms are in its compact size, high rate of fire, and extreme muzzle velocity.

[1] The first projectiles in early gun systems dating from the 14th century were typically hand wrought iron flechettes wrapped in a leather sabot.

The Special Purpose Individual Weapon was a long-running United States Army program to develop, in part, a workable XM-216 flechette-based "rifle", though other concepts were also involved.

In Marko Kloos's Frontlines series of novels, the military commonly use M66 flechette rifles and pistols putting out rounds of thousands a minute.

In Bungie's 1996 video game sequel, Marathon Infinity, the KKV-7 10mm SMG Flechette makes its debut and introduces the player to an extreme rate of fire.

In the Halo video games, originally developed by Bungie, the Needler is an alien weapon that fires homing crystalline needles that explode after a delay.

In Robert A Heinlein's novel The Number of the Beast, the character Deety (Deja Thoris Burroughs-Carter) owns an illegal flechette pistol for self-defence.