On the Starline website, it says 475 Linebaugh, large rifle primer. Now, I've used the Hornady brass and it calls for a large Pistol Magnum primer. Anyway, what are your thoughts on large rifle primers for this cartridge?

Second question: Is the 475 L Starline brass faithful to the original specs (rim diameter) or is it in line with the newer specs for FA revolvers and such?

Thankee

Brian Pierce did an excellent report on the .475 years ago in Handloader. He used Large Pistol Mag. primers. That's all I've ever used. Never had any problems. Have to be careful changing components. Better find a site where someone with pressure equipment has done it. It's an unknown and I would be safe than sorry.
Don't know about Starline brass specs. Ask FA.

Landrum,

The Starline rim specs are the newer specs, not the 45-70 rim spec.

Doc

Thanks, Doc. I assumed as much but one never knows.

About the large rifle primer. I wonder why they would go that route?

The primer pocket is a remnant of the original parent case, the .45/70. That said, just load it with large pistol primers and you will be fine.