What's the proper finish?
 

I'm considering redoing a blue job on my rescued, mismatched DWM. It was chrome plated when I got it and I had that stripped off. I polished it out to about 400 grit which I think was too fine when I blued it a couple of years ago. I'm thinking about stripping it again and doing a rust blue and straw finish. What's the proper grit to use prior to rust bluing?

A 400 finish is fine for rust bluing....the rusting cycles are going to by their nature "matte" the finish a bit. My experience is the first cycle has the most effect on the final finish. It's hard to generalize, but say in a 80 degree 70% humidity environment, the first cycle should be about 4 hours I've found.

Thanks, that's what I was looking for.

I was trying to remember, was trying to sand down a horribly pitted byf and I was told that too high of a sand (I think I was using 600) would really make it shine ;)

I was thinking he told me no more than 300 or 400 / but its been too many years.

Thanks, Ed. I think I may go for the 320 but maybe do some test pieces first.

The end condition or "ripe ness" of the rust blue should look something like this before the next step. I have a few tricks that accomplish this for every application of the rust blue process. The first application is easy to reach this level. The subsequent applications are more difficult.
http://www.lugerforum.com/images/RustBluing1.jpg
http://www.lugerforum.com/images/RustBluing2.jpg