Best way to remove pitting in barrel?

[MRM]

2x for draw file. You could most likely DIY.
Midway has a video on it.

 

[jglenn]

A good cerakote man can fill in the pits with body filler then sand it down smooth
. Blast it lightly and coat it.. had a project.similar and talked with the cerakote folks. That what they recommended..

 

[Horsehat]

If OP’s projects goes like mine, he’s still planning on fixing this.