How are you cutting it? How many are you making?
I found that cutting with tapered cutters requires some extra thought. With a straight cutter, each pass cuts only the depth of the pass. With a tapered cutter, increasing the depth still has the entire length of the cutter removing metal.
I found it effective to first rough out the pocket with a straight mill. Then take the first pass with the tapered cutter opening it to the full diameter at the top. Leave just a small area for a final finish. There will now be a step in the pocket with the top at close to the final diameter. Then increase the depth for the next pass. The key is that only the bottom section of the mill should be cutting.
After this is done, a final finish pass can be made that will remove just a small amount of metal.
Ken
Kenneth Lerman
55 Main Street
Newtown, CT 06470