I finished up 3 guns from the last run that were waiting on semi parts. I tested them yesterday and did the black oxide today. it is a lot of hot dirty work, and the bottleneck of the build process.
the process includes blasting with alox, then glass beads, then 30 minutes in a caustic soap wash, rinse, then 30 minutes in the hot salt. Another wash, then an oil soak. The tanks are my own personal toxic waste site!!
the first picture are the parts ready to be cleaned and assembled, then the finished product.