There's a couple of threads floating about re: an issue with the new Aspire BDC coils not making contact with the firing pin on certain batteries/mods, specifically the Vivi Nova style tanks with the 510 connection. A narrow firing pin, if long enough, will fit up inside the 510 connection on the tank and make contact = foggy days ahead. A broad firing pin, wider than the 510 thread = 0% chance of any humidity. The coil's pin doesn't extend past the end of the 510 connection.

I thought I could file down the 510 connector on the tank so the coil would protrude for the broad diameter firing pins, which I proceeded to do today. No dice. It's the length of the pin in the coil itself that's the issue, at least on six different batteries I have. It's simply not long enough to reach the firing pin. As a semi-noob, I didn't stuff around with trying to pull the pin up on the battery, if that's even possible. As suggested elsewhere, pulling the pin on the coil a mm corrects the problem.

However, I decided to remove the silicone grommet from the coil and then screw into the base, and this worked! Cloudy days! The grommet removal allowed for a mm of extra length towards the battery. I expected to be inundated with juice leaking from the tank, but not even a stray drop after running a full 3mls through. YMMV if you attempt this.