The Sierra manual has some load data for magnum primers , don't know of any other... Honestly I don't worry much about it... I know the load I use is not to hot and I have a bunch of them so I use them... Let your target and crono tell you what's working , a hot load is not necessarily going to be accurate... There's alot of things that can determine max charge , barrel length , bearing surface on bullets , outside temps , it's 108 here right now and I don't shoot in the dog days of summer so I would say my cold weather load would be screaming hot right now , plus the barrels never cool down and neither do I...I have some 450 magnum primers but not sure how much to change the load to use them. The only loads I found for using the magnum primers was Benchmark powder and while it shoots good I get better results with the 8208 and 4166.
I have the Hornady 68gr HPBT match bullets and they are more consistent length than the 69gr Sierra's they are also longer and make the loads hotter. The Sierra bullets vary in length by as much as .007 maybe I got a weird batch?