Will, I see no reason why you cannot set the 4mm stone. That tenth
of a millimeter is no where near the limit…I’ve set stones easily
up to .5mm from the bezel size. Be sure the bezel is not too high as
that will just add extra unwanted metal to to bezel and could cause
crimps. Then be careful when bezeling that you move the lower part of
the bezel in to the stone before bringing the upper half down onto
the stone’s shoulders. Then seat the lip.
Cheers from Don at The Charles Belle Studio in SOFL where simple elegance IS