I believe if .125 diameter pins are used, one would drill .1285 (#30 drill) holes for the scales, but how does heat treat affect the diameter of the holes? Do they expand, do not expand, no change? Thanks.
No change Bill. You got it just right.....a number 30 drill for an 1/8" pin. They will still fit just fine after heat treat. There *may* be a small amount of scale in there after heat treating depending on your method of heating, but even then I doubt it'd be enough to affect your pin going through. If it did, there was probably something else that went way wrong.