#needlegun

Hive scum came out and my life is GONE, send help

Hawkwind - Needlegun (1985) (One of their catchiest songs)

So you're alive, I thought you was done

I'm gonna bring you down with my needle gun

Feel my pin prick tattoo your spine

Theoretically, the advantages of a needlegun over conventional projectile firearms are in its compact size, high rate of fire, and extreme muzzle velocity. A needlegun leverages the principles of kinetic energy and conservation of momentum, resulting in a low-recoil delivery system capable of inflicting significant damage to a soft target. Recoil is generated by the ejecta, which in a chemical firearm includes not only the projectile itself but the hot expanding exhaust gasses, ejected empty catridge and any moving parts. Since the needle is the only moving part of a needlegun (as in a coilgun or railgun), there is inherently little recoil. Although it has extreme velocity, the needle possesses little mass, providing even less potential for recoil. A high rate of fire allows a massive number of projectiles to be fired in a very short period of time, before any perceivable recoil could begin to affect the user's accuracy. Recently, there has been experiments done to make guided flechettes which can home in on targets.

In real-world firearms, terminal ballistics is often at least as important as aerodynamic efficiency. Rather than inflicting their full kinetic energy on a target, needle projectiles tend to pass smoothly through the target with little damage, similar to needles for textiles or medical usage.

A powder-based propulsion system requires a barrel seal, which needles have a hard time providing at high rates of fire without damaging the barrels. Sabot systems result in smaller decreases in recoil (which is proportional to momentum). Compared to a full-size projectile, they allow an increase in projectile velocity per unit of barrel length. A typical full bore projectile might have mass of 147 grains, but a typical Flechette and Sabot for the same 7.62X51 weapon would have mass of only 38 grains, for a substantial reduction in recoil and a very large increase in muzzle velocity.

Lead, used almost universally in firearms for its high density and softness which allows it to pass through rifled gun barrels at high velocity, is unsuitable for a needle for this same reason - it cannot hold its shape without a stronger jacket. Steel jacketed lead core Flechettes are used in some sporting ammunition.