Apologies for the odd thrrad title, just hoping it will help anyone googling with the same issue. Have two Dead Rabbit RTAs and just couldn't get a stable build in either of them. Ohms were all over the place. Builds that should have been around 0.4ohms were reading anything from 0.18 to 0.79 and totally different readings on different mods. Tightening the 510 pin has fixed both of them .