One aesthetic gripe of Sins is the missile effects....for those unaware, missiles have a nasty habit of "missing" their target, and thus having to circle back to hit it (this is purely aesthetic, AFAIK it has no affect on actual DPS)...I highly doubt I am the first to discover this but I do recall a recent thread about the issue where some gent was trying to fix it in his mod (one that had lots and lots of missiles)...

I'd like to draw your attention to these three lines that appear at the bottome of each weapon declaration (in the entity file) that is the type "Missile":

missileStartTurningDistance 250.000000
missileSlowTurnRate 0.708997
missileMaxSlowTurnTime 6.000000

These values are what you would find if you looked at the missile weapons on most (if not all) entities that have missiles (TEC missiles, PMs, doesn't matter)...

First some fine details...if a missile "misses" it's target (ie it doesn't hit but flies past it):

1. The first line determines how far the missile will go before it starts to turn...this distance is measured from the weapon mesh point...in principle, having some positive value here guarantees that the missile will come straight out of the "missile tube" instead of at an angle (gives a smoother aesthetic look)...
2. The second line determines how quickly the missile will turn immediately after it hits the "StartTurningDistance"...in this case, the missile will start turning with a rate of 0.708997 after it travels 250 from the weapon mesh point...the missile will maintain a straight trajectory until it hits that distance, so in general you want this distance to be small...
3. This is a fallback that forces the missile trajectory to aim straight at the target after a certain amount of time...this "timer" starts as soon as the missile is hits the "StartTurningDistance", not when it is fired....this is what causes those immediate sharp turns for missiles that have been flying around their target for too long...

The easiest way to fix the issue is to simply set all those values to zero....one drawback is that missiles will launch from their weapon mesh points at angles...but, you won't have any missed shots....