Doesn't sound like you had this problem, but you might run into it. I've found that stainless tubing sometimes causes the countersink to chatter, giving an uneven cut. I don't have a single-flute countersink, which would probably eliminate the problem, but if I use moderate down-pressure on the drill press and then rotate the chuck by hand, I usually get a nice, smooth champfer of the tube end. I also fill the tube with modeling clay before epoxying it in the handle. Makes it easy to clean up with no epoxy stuck inside the tube.