MT, if you look on page one lower down from the bedding where I show the ring lapping, the bottom photo shows breaking the sharp edge of the lapped rings with a fine rattail file. It's a small round one, not sure how fine it is, but you can see in the photo there's not much tooth to it at all. It's likely a finish file for a chain saw blade.

The angle you see there is about the same on the ramp... you're only "breaking" the sharp edge at the very top of the ramp where cartridges are scratched as they ride over it to enter the chamber. The actual "face" of the ramp just gets a good polish with 600 Emery.

“Perfection is Achieved Not When There Is Nothing More to Add, But When There Is Nothing Left to Take Away” Antoine de Saint-Exupery