7. I think Cartridges of the World had load data - I have never seen it anywhere else. Need to dig out my copy to confirm.
Loading data may be found in older Lyman manuals. Seems like my #45 had data in it. But it was gone in later manuals.
It's too bad that the round is relegated to being merely an oddity. If brass were more common and less expensive... And if it had a .357 dia bullet, it would make a fun and useful plinker.
But, AFAIC, the expense of componets rather rules that out.
Brass can be formed from .357 Maximum, but rims must be lathed-turned and that's a lot of work.
Edw
