I've tried to build Nautilus BVCs a couple of times now, and the good news is that they worked... the bad news is that they did not work well. They were in the 1.5-1.7 range, but I think while trying to place the coil in the head, the cotton got pulled down a little too far. From the top, I added a couple of small pieces of cotton to fill and straighten it out. I used a tiny screwdriver to clear the center all the way through, but the draw was extremely tight and the cloud was maybe half of a pre-made coil.
Anyone have any tips on getting the coil into the head? I have watched the videos on it, but that seems to be the trickiest part for me. I was trying to twist the coil in the direction that the cotton was wrapped... but like SirNutz said maybe I just need more practice. It's certainly more difficult/finicky than your typical RDA/RTA coil builds.