All I do is put the parts in a drill press and sand them using progessivly finer grades of sand paper, I start with a 220 and end with 600 or 1000. Just take your time and don't hurry, for the inside of the reciever use a 3/8 inch dowel with a slot cut lenght wise in the end and wrap a strip of paper around the dowel, if it's snug and makes the receiver start to warm up you have the right amount. For the truly retentive you can also use a polishing compound for car paint on a damp rag to get the mirror finish, the bolt is softer than the receiver so it will start to scratch in time, take it apart and redo if it bothers.