ya mold..there is no need to get over 60 fps, just a need to stay over 45fps. That is the important part.
As far as the tracers go, I was watching heavy metal today on the History channel, featuring the p38. The smoke from the tracers is barely visible. I guess, if the air is warm and moist, the smoke from the flare on the bullet is not so pronounced. I would suspect, in cold dry air, or perhaps just cold air, the smoke is more visible. In any event, the key to the tracer problem is not the smoke from the tracer, but the glow of the projectile itself.
Just the right length, perhaps a little jiggle, maybe a hint of spiral (tight!) smoke. But the damage effect as the bullets ripped through the zeros is really the hook. In my opinion, HTC has very nice damage effects in AH, keeping in mind having to keep the frame rates workable for online play. I say, focus on the projectile, not on the path it travels.