This is my initial comments about those new tracers...

Its a start...We will have to see those in action...I was watching one of the (hundreds!) of COD's video in slow motion, and I noticed that the last fired tracer " appears" almost at the same place as it predecessor....And all tracers being identical in length and brigtness, it gives this strange and unnatural flickering effect we see. So instead of being able to follow one tracer until it fades away, it looks like it has been "replaced"....Also, the effect of " slowing speed with distance" is not well implemented yet....
I beleive IMHO, that when those issues are fixed, it will be very good RL representation...Until then, this is a step in the right direction....

Salute !