david weaver
The point is whether or not there is any reasonable set that has the cap iron below the plane. Not necessarily can you, but is there any reason to.

But I still haven't gotten to the "can" part, and maybe it's because I'm not measuring. If I have time this weekend or next, I'll measure setback with the microscope and try again.

To date in five years, though, I've never had the cap iron protruding into the cut. As warren says, those kinds of sets would give me the willies, and I've found things to go backwards quickly before you get to them.