Dirt, yes, the high temperature exposed tests that I ran was with Swift A-frame bullets. However, they were handloads, not loaded factory ammo.
I checked my reloading info, and I was using 79gr. of RL15 with the 400gr. Swift A-Frame. For solids, I used the Northfork flat point solid and bumped the powder up to 80gr. for that. I know you're most likely going with 4064, so that info probably doesn't help. I did a lot of work with 4064 in the .416 Rem, but I was using the 370 gr. (I think) Northfork soft point for that work. I was never able to get consistent accuracy with the NF soft, so abandoned that and went with the Swift A-frame. Looking back, I'm amazed and how much $ I spent trying to make the NF bullet work for me. Lots of rounds downrange!
By the way, in case you didn't already have the info, my old (#1) Swift reloading manual shows a maximum load of 78 gr. of IMR4064 for the 400 gr. A-frame at 2409 fps and says that it is at 96% load density.
