They are .355" made for the 350.
I'd start at about 24.0 H110
Hodgdon has data online.
I got a stiff bolt lift at 26.0.
I had a load worked up for my Ruger last year. Got a Savage recently and the loads were blowing primers and also losing chunks of brass at the neck. That was with Maker 150 TREX and Lil' Gun. Going to back off a grain or so and see if that works
