A little bit of the dovetail is available to measure on my 92X, and the front seems like .220 and the rear is .300. This seems bogus. I used the tail of the calipers and kept it as square as possible. I suppose the rear could be .290, which is what WC website says. But the front is nowhere near .140, unless one measures against the top of the slide, not from the bottom of the dovetail.