Speculation on near-future hard sci-fi, often with reference to GURPS Transhuman Space (TS). Occasional digressions into other fields such as cyberpunk, ribofunk and Car Wars. If you have enjoyed this article or it has been helpful to you please feel free to show your appreciation. Thank you.
Thursday, 22 December 2016
Weapons: 8mm Flechette Rifle
The 8mm flechette rifle is a weapon that is usually encountered in the hands of security guards. Users favour the weapon for its flat trajectory, high hit probability, low recoil and effects on unarmoured and soft-armoured targets. Its limited range and poor performance against hard armoured targets have precluded it from military adoption. Their minimal effects against hard armour can be exploited if friendly forces are armoured and the enemy is not. American insurgents and some criminals have also made use of stolen weapons.
The 8mm diameter polymer cartridge is straight-walled other than a slight bottlenecking at the end used to headspace the cartridge. Each cartridge contains a sabot that holds five 1.5mm steel flechettes. The light weight of the flechettes gives them a muzzle velocity in excess of 1,100 yards/ sec. At short ranges penetration is high and trajectory is effectively flat. At longer ranges the projectiles rapidly lose velocity and will be affected by cross winds.
Although they are commonly referred to as “flechette rifles” the weapons that use the 8mm round are usually of SMG configuration. Barrels are effectively smooth-bore, having a slow, shallow twist to aid sabot separation and flechette dispersion. The 8mm round is well suited to a simple blowback mechanism. The simplicity and low cost of such weapons is another feature that recommends them to security forces. Typically a reflex sight (+1 to Guns skill) is fitted.
Guns (SMG) (DX-4, or most other Guns at -2)
8mm Flechette Rifle
12 x 5
Real world note: Relievable information on the terminal effects of flechettes has been hard to come by.
The original claim of the SPIW project was that flechettes that hit denser materials such as flesh would bend, dumping all of their residual energy into the target.
Another source claims that the tail of the flechette tends to stabilize the projectile in flesh too so flechettes are not prone to tumbling, giving poor energy transfer. Evidence for bent flechettes, it claims, is from wounds inflicted by multiple flechette rounds fired from recoilless rifles, tank guns and artillery. Flechettes were bent by the stresses of firing, not impact, it is claimed.
During the ACR rifle trials it was claimed that the flechettes used by two entrants “fishhooked” reliably.
Terminal effects are more about damage than just energy dump. Even if the flechettes do bend and tumble the real question is the rate, depth and damage that occurs as they do so.