Thats what I've been trying. Then when it starts to get a little offset bent I use the body work hammer and tap it back a little. That's actually how I broke the little nipple off of the flare attachment.
i just take the burrs off with a fine tooth file. straight across the face at 90' and then lightly around the outside to take the hard edge off. everything is nice and smooth then and the insert can roll the edge properly