I only have limited experience with corner rounding end mills but generally I don't seem to be able to run them too fast. I suspect you're not feeding fast enough or there is something wrong with your cutter such as insufficient relief. I would run the cutter at a feedrate between .005 &.015" cpt & 10-20Krpm. Lay the profile out in a CAD drawing or blow it up on a piece of paper. You'll see that the quantity of material you're taking of is miniscule on a .1875 radius. If you're running dry, I doubt a standard cutter would have proper clearances.