Connor no, I am surprised you are not familiar with this topic, I thought Millard or Hogg or Big Karch had made this a sticky topic here on meso a long time ago. Maybe I am wrong about that. When you load a syringe for an injection, there is an invisible amount of oil in the neck of the syringe that you cannot really see, it is basically invisible oil, but it is there, there is nothing you can do about it and you have to account for it when you are determining how many cc's of oil are in a vial. I call it "waste oil", that is what I have always called it. For example......you pull up 1.3 cc's in your 3 cc syringe......you measured 1.3 cc's by the little ticks on the syringe barrel. But there is an additional "invisible" .10 cc's of waste oil in the neck of the syringe - you cannot see it but it is there. So if you pull up 1.3 cc's of oil in your 3 cc syringe.......you have actually withdrawn 1.4 cc's from the vial, not 1.3 cc's........ 1.3 cc's of visible oil in the barrel plus an extra .10 cc's of invisible "waste oil" = 1.4 cc's.
So if you were to open a fresh new 10 cc vial of gear, load (10) 3 cc syringes with 0.9 cc's of oil in each syringe......and afterwards you have completely emptied the 10 cc vial....then that 10cc vial of oil originally contained 10.0 cc's of oil, not 9.0 cc's of oil. This is because in each syringe you loaded up, you had .9 cc's of visible oil in the barrel plus .10 cc's of invisible "waste oil" in the neck of each syringe. You have to account for this "waste oil" when you are trying to determine if a vial is accurately filled or not.
A lot of guys on the AAS boards will make the mistake and say ...... " (10) syringes X .9 cc's per syringe means there were only 9 cc's of oil in the vial, so this vial was underfilled by this source to only 9.0 cc's." And Connor, that is WRONG. That is not true. The 10 cc vial of gear is not underfilled with only 9.0 cc's. In fact, that 10cc vial was accurately filled with the correct 10.0 cc's of oil by the source.