If you overdraw, then push to the line,in this instance the 1cc line, you will have overdrawn aprox .2cc. This is because the tip of the syring is also full.
If I am drawing 1cc, I pull the plunger down to the 3cc mark, then let it fill to the 2cc mark. After that I push it up and remove the air, it only takes 1-2 drops to lubricate, then in it goes.
My first cycle I used the "overfill push to line method" on a bottle of homade tren. Even though I measuerd the cc precisely when making it, I came up short at the end, as if it were underfilled. The next time around I used the other mothod I described, and had no issues with it seeming underfilled. Thus I have used this method ever since.