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.
Monday, 18 January 2016
Flight times for Homing Ammunition.
When firing homing rounds they may take more than one turn to reach the target. Basic rules (B p.413) say to use any 1/2D figure as projectile speed but this doesn’t really work for small arms. The following values can be used instead to give a simple but reasonably realistic performance. Bullets get slower the further they get from the muzzle so for the second and subsequent rounds speed is generally halved. Projectiles that travel at 375 yards/sec or faster exceed the speed of sound, creating a very audible bullet-crack.
·15mm micro-missiles and 30mm mini-missiles: 500 yard/sec. (Will usually hit in same turn that they are fired).
·4mm and 10mm pistol/PDW: 350 yards in first second, 175 yards each second after. (The 4mm has a higher muzzle velocity but the 10mm retains more energy down range so for convenience average velocity is treated as the same for both). Muzzle velocity exceeds the speed of sound.
·5.6mm and 6.6mm rifle: 600 yards in first sec, 300 yards each second after. (Higher muzzle velocity of the 5.6mm is balanced out by better sectional density of the 6.6mm so average velocity is treated as the same.)
·7.62x39mm AKM/Maku: 500 yards first sec, 250 yards each second after. Generally these weapons use non-homing ammunition.
·7.5mmMG: 700 yards first sec, 350 yards each second after. Uses a heavy streamlined bullet designed for target effect at long range.
·9mm MAX and Subsonic Ammunition: Treat as 300 yards first sec, 150 yards each second after. Generally 9mm MAX weapons use non-homing ammunition.
·Plastic Ammunition : Half speed of standard type (therefore Plastic subsonic ammunition is 150 yards in first second, 75 yards each second after.)
·Supercavitating 15mm mini-torpedoes are move 25 for the first second, Move 40 for the next two.
·Supercavitating 30mm mini-torpedoes are move 30 for one second, Move 80 for the next three.
·Supercavitating ammunition fired underwater has 1/10th the speed of a normal round of the calibre.