I bought a natural today and the only batteries that particular shop had were button tops. I didnt know any better at the time but after fiddling with it and trying my friends flat top battery, *DAMNIT*. those are the ones i should have bought. Any one know any tricks to get button tops to work, that doesn't involve excessive modding. i currently have the efest 18650IMR and 18350IMR (pretty standard) and they leave the slightlest gap that annoys me ( as it does most people). any input would be great! (besides go buy flat tops)