I duplicated the chamfer by hand on a smooth grinder. and it seems like I had to fit the bullit guide slightly as well. it took a little fittting to get it to work right. I honestly cant remember on the guide it was three years ago. I did the fitting with out the barrel in place Just turning it into the trunion by hand.
while you are at it double cheack that the bolt face is milled/turned flat all the way across were the bullet hits it. On two of the three Kvar 223 bolts I have the face has a bevel in it that prevents the case from seating all the way down flat. it looks like from your pictue (hard to tell) you may have the same bevel were the face meets the side . its likely caused from a dull end mill. this will raise hell with your brass rim and if it is relaoded the head space will be loose on it. I bought a metric end mill and trued mine up.