So I got my VS rDNA 40 last week and I am having an issue with the 510 connection. Basically what's happening is that when I put one of my rda's either the plumeveil 1.5 or the stillare on it, it wobbles. I have tried tightening down really good and they still wobble around. It does not do this with my kayfun 3.1, kayfun lite plus or the Aspire Atlantis. I have no clue what is going on or why it's doing this. I have not contacted vapor shark yet but just wanted to know if anyone out there has the VS rDNA 40 and is having this same issue or anyone who has a previous VS that can comment or suggest anything. Thank you for your time.