"Steve Peterson" writes:

This sounds like a good candidate for loose tenon joints. Are you too far
along and too committed to integral tenon?

I'm not having the problem. Mike suggested cutting a dummy mortise to
find why the real M&T wasn't fitting.

I'm just saying instead of cutting a dado, which will fit 2 sides, and
may not be deep enough, to glue up a mock motise with p`4 pieces of
plywood. A tablesaw can cut pieces squarely. You might be able to
use a rubber band just to hold the pieces together.

Personally - I would first try the "look for the shiny bits" method.
Or inside and outside calipers (if you have them).
And only use the mock-up if you can't find the problem.

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