I discovered my cheapie miter gauge is also sloppy, but it is pretty loose in the miter slot on the saw and the jig. So, I ordered an Incra MITERV27 without the fence for now. Hopefully I can get it to work.
I had a problem some time ago with a poor fit on a miter bar on a jig, which I fixed with aluminum duct tape, used as a shim on the side of the bar. One layer seemed to do it. .0060 is more error that is workable for something with 7-8 miter joints. The whole point is being exact and minimizing the problems of assembly.
Since the jig is closeer to .7500 than the saw slot, I'd try to work out a way to fit to the jig. Try the aluminum tape, but be very careful to get it perfectly flat. At least it will come off (leave a little tab on the ends for removal). I don't have anything precise enough to check the thickness of the tape, but if you do, kindly let us know--maybe a before/after. It will go in the slot, not on the gauge.
Changing the width of the Griz's miter slot on either side should provide the precision you need. It is all about getting the miter slot parallel to the blade, the distance from the blade isn't a factor.
The more I do, the less I accomplish.
Last edited by DesertRatTom; 08-21-2017 at 10:44 PM.