make sure you COMPLETELY disassemble as the media will get into ALL areas. You will need to remove the extractor as grit will get underneath. Also be aware that be removing the extractor, you may change the reliability of extraction if its not check with proper tools by a SW Armorer.
make sure you remove the sights as you dont want to blast them and plus the safety plungers need to come out.
DO NOT bead blast your slide and frame rails or the inside of the slide where the barrel locks and rides. they will not be smooth sliding if you do. cover those areas twice with masking tape and minimize your blast time in that area.
if you plan to bead blast your barrel hood exterior, mask off the locking lugs and the chamber or feed area. I have also protected the breech face as I want that smoothed by wear.
I am no pro but I am hard on the guns that I carry so I have to redress them every now and then. I have a buddy at a machine shop and he lets me use his blaster!
I lightly dehorned my CCO slide and then bead blasted it. I do not know what coarse and control the finish by air pressure, distance and time blasting.
pre blasting
post blasting
I also bead blasted my Officers ACP and then 320 polished the slide flats
I also redid my CS9