Ken, I have not tried bead blasting and avoid items with rust problems...I am working from the approach of an engraver which leads me to Craig's comment. I have only done the prep with the intent to engrave the item and without toning down the case hardened surface engraving is very problematic to totally not doable. Like trying to cut glass with a graver. None of this is directed to modern metal firearms that are through hardened...those I either cut as is or turn down the job. Some of the stainless guns can be very very difficult or impossible to cut.
Most of the engravers who have commented on annealing cch parts say temps in the 500 to 900 degree range are all that is necessary and coating with something like Brownell's pbc scale preventer works well.
That's interesting, considering that it's usually pointed out that the parts need to be brought to above 1333F for annealing. The lower temp would "Draw the Temper", (semantics, I know, but is really a stress relief measure usually used after case hardening) but would not be true annealing. Annealing, as was mentioned by Doug, requires parts being packed in a crucible with charcoal, (I think wood charcoal only for this could be used, no need for an energizer like bone) the crucible then being brought to above 1333F and allowed to cool down inside the oven. If this is incorrect, someone please speak up.
Temperatures used for the coloring heat seem to be all over the place, but from several sources I've read it was stated that after the crucible was brought to above the critical heat (1333F) and held for a period, the temp could be reduced 200C before quenching. This would prevent warpage yet still result in excellent colors.
