Originally Posted by janice6
Be careful. To a machinist, exact size is a "press fit".
Most of the bigger holster makers use a 'bluegun' or a facsimile to mould or form their holsters. Should your maker have one? Dunno.
G39 slide width is 30mm or one and three sixteenths inches or 1.18"
Hope this helps. Disclaimer YMMV.
Post up a pic of your new rig if you decide to have one made.