I think I’ve loaded it every which way at this point, and it actually seemed to do worse as it got hotter. But I’ve got a lot of it, so I’ll keep trying until it’s used up. I think I’ll make some test loads just for this purpose, with different crimp levels and charges. I think it will only take 1 round per load because one can just look in the fired cases to see whether it made crumbs or not. Maybe a really heavy crimp will help.
The max charge is a bit of a mystery. In 158gr .357M jacketed, the Shooters World reloading guide gives 12.2gr, the canister says 13.1gr, and the Lovex guide goes even higher to 13.4gr (but with a stated pressure of 43500 psi). The Lovex recommended load is 10.8gr, which was super wimpy and also dirty for me. As I recall, even 12.2 felt wimpy for a magnum and showed no significant pressure signs. 13.1gr felt normal and showed flattened primers more like a stout factory load in the same gun, so I think the canister has the more reasonable value.
Perhaps hot enough for this powder is super hot in .357M. In that case I’d still be unhappy with it, even if there is a way to load it.. I wasn’t looking to replace H110/W296 for max velocity.
I should add that it’s pricks on my cheek with virtually every shot that are annoying me. I don't get that with any of the other powders I'm using. Apart from that it seems to shoot OK at a wide range of power levels.