I would like to end up with about 1/2" of telescope showing.I have an 18650 in there screwed all the way now and am afraid it could be too much for penelope pin (and/or bottom spring)... I would like that gap to be a little smaller yet. I tried an 18490 and that is too close.I have no 18500 but will an 18500 make a diff? any suggestions would be appreciated.