Gunsmithing Aluminum Oxide source?

Re: Aluminum Oxide source?

Many thanks for all the suggestions. I can get 90 grit at Tractor Supply but I was under the impression that 120 was the stuff to use.

Anyway, the M4agery's extension tube is the Guinnea Pig. I had to do a lot of hand machining to get the new buttstock on so I'll try out the process in Graphite Black.

Many thanks again,

CT