Join Date: Sep 2012
Location: Wilkes-Barre, PA
It looks as though the height settings of the two profiles are slightly different. This shouldn't cause a gap, but you never know. Before sending the bits back as faulty, I'd triple check that they are set perfectly for height and depth, that your fence is set perfectly, and that the tenon (on your cope cut) is making 100% contact with the rub bearing in between the cutters on the rail coping bit.
If you can verify all that, and it still doesn't fit, send em back. They should fit perfectly. No clamps, no filler, perfectly. I only clamp my doors ever so lightly to snug & hold them together while the glue dries. Too much pressure absolutely will bow the doors.
Ive never used MLCS bits. I have 2 sets (different profiles) by Freud and never had an issue once set up properly. Let us know what you come up with.