Yes lead will produce higher velocities with the same charge than jacketed. Glad it all worked out for you. My tinkering ability is not as high as yours, I've decided not to cast, and will test a range of on the market bullets and jacketed bullets to see how they go on medium game.
As to ADI powders if you are getting AP-70 there I assume you can get AS-30N(what Hodgon in the US markets as 'clays' ). Might be worth a look, faster burning than AP-70 (which is what Americans market as 'Universal clays', different from regular clays).
https://www.hodgdonreloading.com/data/pistol
From hodgons reloading manual for 357 pistol , 158 grain cast
3.2 clays(As-30N) 867fps
4.6 clays (As-30N) 1079fps.
This is a pistol barrel, you should get an extra 80-120fps from the rifle barrel.
The max load listed for trailboss is 4.2 for 865fps in the pistol barrel which probably equates to your 945fps from rifles.