A favorite of mine is this:
115gr RMR JHP, 13.5gr Accurate #9, CCI SP, COAL 1.131", 1450 FPS guesstimate.
I like the case well filled to aid in the prevention of bullet setback.
Data can be found on page 408 or the Lyman 50th Edition.
In violation of the title of this thread I will ratchet jaw forward.
I'm using the Lee Factory crimp die.
It's a fine line between getting a crimp that holds the bullet firmly
yet doesn't crush the case.
If I trim the cases to 0.860 and use cases that are 0.859 to 0.861 with
that amount of spread I can still get a good crimp. Needless to say
I don't trim the cases that measure 0.861!!
I have cases as small as 0.849... they work fine but I have to adjust the
crimp die to get the good crimp.
What I do is I set the crimp die to a center size and use cases that
vary 0.001 on the + or - side.
I am so satisfied with the crimp that I get that I will be trying some
of the faster, lower quantity powders, and not be concerned to having
the full case to help preclude set back of the bullet.
Getting a handle on the 357SIG crimp has aided me immensely in
loading the 300 Blackout.