Eagle27...I wouldn't call my friend an experienced reloader, he's only been doing it for a short time. He's not one for the computer either, so when he has a question, or hits the wall, he asks me. When he asked me about the 416 loads initially, I looked at the 416 RM data in the loading manual, seeing the case capacity is only slightly more than that of the Ruger. It listed a start load of 76gn 2208 & a max load of 82gn 2208 behind a 350gn bullet. I suggested he start at 75gn & go from there...which is what you suggested!
I think he was after something more concrete, because I could tell in our conversations that he wasn't too confident, hence contacting ADI & asking the question here.
Thanks for the replies.
Cheers