Is this a cartridge aka cart which is used with an atomizer? I never got any prefilled 510 carts but they have a rectangular
juice cup and you should try to orient it with the atty bridge this way
[==]
_/\_
If you mean the actual mouth end with the air hole came off - wow no clue - sorry.
Or do you mean a cartomizer aka carto which screws on to the battery? And if so what kind?
I cannot picture what you ware talking about. CE2, Clearomizer, Fluxomiser cartos have an inner seal (possibly 2) and you are supposed to use a special syringe (I think with a flexible tip) to fill them
through a hole or port in the seal under the mouth cap. If you removed that inner seal, the orientation is with the side notches fit on something in there.