I messed them a long time ago. From memory:

<Lifetime>25.0</Lifetime> - How long the rocket/missile/bullet lives (displayed on the screen).
<CtrLifetime>25.0</CtrLifetime> - I'm not sure of this one, but I think it refers to how long the radar guidance lasts.
<EngThrust>20000</EngThrust> - Amount of thrust of the rockets/missiles/bullets. Increase or decrease to change the performance.
<ThrustDuration>10.0</ThrustDuration> - Length of time that the rocket engine runs. Increase it and the rocket power lasts longer = further range.
<SelfDestrTime>10.0</SelfDestrTime> - Length of time before the rocket/missile will self destruct. From memory, this is usually the same length of time as the thrust duration.