How much juice are you putting in? I had the same problem the first time I filled mine, then I remembered. The air holes are lower than the top of the base, so you can't fill it as full as you expect to be able to. (Although maybe if you had a lot of cotton in there to absorb extra juice you could).
The airflow is low to add flavor or something, and it seems to really work.
It's not overfilling. It's condensation, I think, running down from the inside of the cap and getting behind the AFC ring. It happens the longer I use it. When I unscrew it to refill it kinda oozes out by the threads. I put the o-ring in that bit of a gap below the threads. Bonus is that is holds the ring in place. Even if it doesn't help with the leakiness I'll be happier without the ring spinning free.
The airholes are only lower on the outside of the Magma. They are level with the deck. My leaking issue is only after I open it. After that it just gets so messy all around that ring that I can't stand it. (OCD) It's a love-hate relationship. LOL
My very favorite is still the Atomic. Great flavor on that tiny baby. She never leaks on me either. Trade off is she doesn't hold much e-liquid.
