Any welding shop or machine shop can do it real cheaply.
Bead blasting is gunsmithing?
Bead blasting is gunsmithing?
Source: ATF Online FAQ
Q: Is a license needed to engage in the business of engraving, customizing, refinishing or repairing firearms?
Yes. A person conducting such activities as a business is considered to be a gunsmith within the definition of a dealer.
[27 CFR 478.11]