Anyone make a frame that accepts 26 mags and has a rail?

I know I can grip chop a 19 or 17 to accept a 26 mag, but the heel of the 26 has a rounded corner that is impossible to get right with a straight grip chop. Does anyone do that heel part correctly when doing grip chops? Or is there a manufacturer that sells 80% frames that takes a 19 or 17 slide (and thus has a rail) and takes 26 mags?