Thinking more of this I get a bit split about this as I have also been personally complimented by Oleg earlier for my explanation about how the tracers get 5 meters long (and that is naturally fun!)... Sure - the "long" tracers are fine if we simulate a camera looking at an mg firing tracers, but in that case we actually should really have the zig zag too... Get my thought? Because when looking at a real tracer that is fired (and not from a video or an image) it goes like on rail like I described above - but it looks like a tiny superfast firefly zipping from your barrel out into the night. No long light streak but tiny white glowing dots popping away towards the target (and then the chaos of ricochets going of in all directions that no game has ever been able to catch). It actually looks very surreal and not like you could expect from seeing movies. You get some strange feeling of not firing a gun but more of some kind of super powerful "sling shot" as you see the bullet popping away over the field and then bounce... But like I said - just a tiny glowing dot and no "streak"...
So - if you are going to have the streak then you look through a camera lens and then you should actually have the zig zag too (even though I said the opposite above I'm man enough to admit I changed my mind
)
Edit again - having said this I also say "what the heck"! It looks good enough as it is (which goes for the landscape too) so focus on real problems now like optimizing net code so that a bullet that really should hit its target does it, don't care that much how it looks
Triple edit - looking from behind at the tracers I also guess that you may need to have the long "streaks" to get the feeling described above as the tiny dots would not be seen otherwise. Looking from the side it may look a bit weird but if you miss a 1x1 yellow pixel otherwise you have to make compromises like this...