Don't use a downcut bit for profile cuts like this! An upcut bit works much better, puts less stress on your tool and provides a cleaner profile cut. Downcut bits force all of the chips down, so when you're taking multiple passes on a profile cut, it's like cutting concrete by the time you get to the last pass as all of the chips compact at the bottom of the cut. An upcut bit is the opposite, it forces all of the chips up, putting less stress on your bit and allowing it to create a cleaner profi