I think what he's trying to get at is: If a tracer in the game were a 2-inch diameter unguided missile (streaking by you and leaving a 2" diameter smoke/tracer trail as it went on it's merry way), then what the OP is requesting is that it be reduced to say a 1-inch diameter.
If I got that right, then I agree, all tracers in the game as they streak past you seem like they're cannon-sized rounds. It would be nice if the smaller non-cannon rounds left a smaller diameter tracer as it whizzed by you.