Starting load for 357mag (S&W revolver)

Can anyone point me in the right direction for a starting load, for: S&W 686 revolver (357MAG).

powder: ADI AR2205
bullet: 158gr RNFP; hard cast from HRBC

I also have AP50N if that’s easier. And Trail Boss. Bah, seems like I am accumulating quite a collection here. Anyway, just a force of habit, since I use 2205 in 44 and 357 carbines, hence said that, but above are alternatives. I just figured 2205 seems to be the go for those things.

Anyway, suggestions appreciated.

Havey’s Manual
Starting load for JHP is 14.5gr of 2205. But seems a tad hot for cast, maybe?

AR2205 is garbage powder for 357, always ran dirty with unburnt powder left behind. AP50 was better, but AP70 has proven best in all my 357’s from the 4" S&W Model 13 through to the Pythons and Troopers. my AP50 load for HRBC 158g SWC 5.6g, I now load the same pill with AP70 at 6.0g
which gives me 85 to 90% of the Military Loading, Cheers.

Awesome, AP50 it is.