That's a pretty significant difference, but since it was prewound I guess something could have gone horribly wrong, including a 0.35ish coil getting slipped into a box of 0.6s. It's really hard to tell. Did you "do" anything to it while installing it, like unwind one leg halfway or something? Is everything really secure on your atomizer, like no loose legs and whatnot? Do you have another mod to test it on or an ohms reader, and if you do, is the reading more or less consistent? Did you space a contact coil or vice versa?
Can you post a pick of the coil and its instillation for the pros to look at and comment? Something is probably off, the question is what.
You want to figure this out probably before you go vaping on it.
Anna