I now have a round file that I file from back to front going away from the ferrule. Prior to that and often still do, I used the narrow flat of a ten inch file, pulling it while holding the file backwards and using the ferrule as a guide. I have found that the RADA wheel can be a weak edge on some heads, after killing a deer the filed edge holds up better on softer metal heads. You can tell when it is getting close the broadhead will have a soapy feel under the file. That is when you want to go with lighter pressure. I finish with a jewel stick and an old belt. I get a hair cutting edge that I would not want to shave with.
With some heads I use a Grizzly file only. The Grizzly files had the round narrow edge that can be used like a steel, but the cutting teeth end sharply and are very good for putting a fine saw toothed edge on a broadhead. That fine sawtooth edge, no matter how much better scalpel sharp is forensically shown to be, will cut arteries very nicely and leave good blood trails. I have never had masses of hair and fat get pulled along with the serrated edged broadheads and I have never lost a deer that I hit with one. Dr. Ashby wrote of how he lost two out of over 40 animals sharpening Hills with a file. A mule deer that got stolen before he got to it and a bear that dove into some boggy stuff and disappeared. On some heads like Deadheads and Grizzlies, I go with razor sharp and use different methods.