Well, every weapon is different with "phantom reach."
Take the Elite Scimitar for an example, I'm going to quote from Kafein's post this time.
It has a ghost reach because even if the end of the model is curved to the back, the collision model is an axis that follows the grip of your hand. So when your target is at top reach, you hit before the model actually hits. And that is not all, as the real reach is roughly the distance between your hand and the model end, it is greater than simply the distance between your hand and the projection of the end of the model on the axis.
- <- where your reach actually ends
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in red : collision axis
As you can see, the weapon hits way earlier, because the egnine thinks it's a straight sword.
Range on the other hand, I don't know, but some weapons have a weird feeling of range if you ask me.