Improved One Shot
The Improved One Shot (I-OS) missile system was developed during the Clan Invasion by the Draconis Combine. Draconis Combine Mustered Soldiery techs took a standard One-Shot system and removed the ammunition feed tubes from it. The missiles were stored directly in the launch tubes instead. This allowed the Improved One-Shot to be lighter than its standard counterpart. The tradeoff, of course, was the lack of any reloads for the missile launcher.
Like the standard One-Shot launcher, the Improved One-Shot can use any appropriate guidance system or munition.
Improved One-Shot launchers weigh half a ton less than their standard versions. The minimum weight of an Inner Sphere launcher is half a ton, while the minimum weight of a Clan I-OS launcher is a quarter ton. In all other aspects, the I-OS launcher is treated as a normal launcher of its type.
- Tactical Operations, pp. 326–327: "Missile Launchers - Improved One-shot (I-OS) Missile Launcher"