Take
batteries out of your
mod, put everything in freezer, often causes metal to shrink a bit.
Next time use rubber bands around the 2 parts and twist w/washcloth or something, pliers can do damage.
It sounds like your
threading had some burrs....before use next time clean good, naolox the theads or use a pencil (graphite will lube them) then clean that off carefully with a cloth, should take the burrs down if there are any.
Edit: Oh wait, you can't take batts out of MVP2. The batt is stationary. Maybe use the pencil lead or some naolox / graphite on areas of the threading that is still exposed?