I used felt wheels on a Dremel for the tight areas, and my buffing wheel on the car polisher clamped in a vice for most of it using a metal polishing compound with both tools.
The grip is after market Volquartsen, it can be used left hand but its not very comfy.
I also polished the feed ramp and the bolt seems like the bolt is smoother but unsure if polishing the feed ramp will help with anything as it didn't have any cycle issues before.