ArchAngelCD my Speer # 13 manual says 17.5grs 2400 with a 125JHP
and CCI 500 is within current pressure max. for 357 mag. of 35,000 psi.
As has been discussed here before there is little to no difference
between the 400 and 500 as to primer energy and my own tests with
loads using 2400 show very little difference in velocity between the two. My lot of CCI 500s are very difficult to seat and do show more
flow back into the firing pin hole than any other primers I have and
so they are relegated to light loads in old well used 38spl cases. Pre
Hodgdon data from Winchester shows 8.1grs of 231 with a 125gr JHP
at 42,500cup with primer unspecified. And yes there is an obvious
difference in primer appearance between the 296 and 231 loads using
the same primers. My assumptions are just that; assumptions. I
think any of the three loads should be fine in any sound revolver.