I am working on forming 100 rounds of .348 into 45-75. I am waiting for some neck expander dies from CH but I will be at the fire forming stage in about 5 days. I have been looking over all the posts on this process that I can find but I am still confused. I have four powders on hand, Black, 4198, Tight Group and Red Dot. Its a bit tough to get powder at this point so it would be best if I can use one of these. I have a bunch of 320 grain bullets on hand. Can someone with experience doing this give me detailed information on how to go about it? Which powder and how much to use, if I need a different powder or bullet etc.
Thanks
Roscoe