In image A you have filed to far across. Had you filed to half way the usual result is the shift is away from the most material removed.Let me ask it this way:
Looking down on the barrel, as in top view:
If I file barrel A as shown across the muzzle, which way will I move the pattern?
If I bevel the INSIDE of barrel B halfway around on the side circled, which way will the pattern move?
Thanks
oops! Forgot to add the pics, lol.
View attachment 256793
View attachment 256794
In picture B, the pattern should move away from the bevel.
The process is reversible if you go to far.
Do not remove more than .040"! More is not better in this case!