Ok I just bought a brass nemesis from vape doctor and when I put my 18650 flat top in it and tried to fire it but it didn't fire I took one of the extensions of so it would shorten the length and still nothing I made sure my rda was making good connection but still nothing and I know it's not the battery because it works with my other mods same with my rda when I put my battery in it it rattles around I have no idea why please help