It’s different between picture of tracer 17 in Atlas and mounted on my ship. when it on my ship, it uses a basic plasma gun’s model.
Is it wrong or unfinished?
It’s another inconsistency between the atlas and the actual model it’s meant to represent. In this case the model is of the lowest rank plasma gun which the tracer reuses. But in this case the Atlas’ icon for tracer doesn’t reflect the change in model between ranks as the one on your ship is of the highest rank plasma gun.
Yes, you are right. All tracers reuse the basic plasma gun’s model of same level, but in atlas it only uses the lowest level one’s picture.