Need help! New here. H322 start load for 4570 henry

[Pumphandlerandall]

Hi so I'm new here I figured this would be the best place to reach out I had trouble figuring out how to even post a thread so if I posted in the wrong area my apologies. So I cannot find any safe published data for a load I'm trying to work up for my new Henry Steel lever action 45-70. The only powder I have to my knowledge that will work is h322 and I'm supposed to go to the range tomorrow and I really want to make these loads. I have only berries 350gr rs copper plated.... I actually have several 45-70 molds but I'm waiting on a sizing die I tried testing and slugging the barrel and they will barely go in and extract so they need to be sized so this is all I have to work with for now and I just want a decently safe starting load that's not going to blow the gun apart in my hands normally I'm not too shy about loading I'll load full power h110 loads for my 460 magnum as long as it's published data. But I can't find any on this 4570. I do have some other powders and I read that some other powders can be used but I don't think I have any that can be I'm mainly a hogdon in person I really like their powder and it seems to work well for me. My guest based on my research would be somewhere between the 40 and 45 grain range for a starting load for that size bullet to keep it under 30,000 PSI? Any help would be appreciated thank you

[PAndy]

Google search speer load 45/70

[243winxb]

https://hodgdonreloading.com/ Hodgdon data has 3 different 45/70 sections of load data, based on the strength of the firearm.

The lightest starting load is- 36.5 grs of H322 with 325 gr jacketed bullets.

[Eddie Southgate]

There's an echo in here !