sounds like you are doing everything right.

When I am humming at the range I buzz my arm just a tad with the string. Not enough I need to wear an arm guard, however its enough I can feel it with an arm guard on. Was working on trying to adjust to get rid of it this spring as I do quite a bit of really cold weather hunting. Figure if I can get rid of it now, it will be minimal to non existant when I put the marshmellow man suit on. Maybe someday I'll get it right?