I'm working on the RL26 and 200 partitions for an all around load.
As far as published data goes, the closest I can get is my Sierra manual for 200gr bullets. It brackets RL26 with 7977 and H1000 (burn rate chart). The max loads are 58.7 and 58.1 respectively, with 2450 from a 24" barrel.
Based on that, I would think ~58.5 would be a max and 2400fps from my 22" Winchester would be near pressure. Not knowing the bearing surface of the two bullets and pressure differences will be a factor also, not sure how to handle that. I read a guy once that said once you see brass flow you well past pressure limits.
I'm not understanding these 60gr and greater loads, unless the Partition produces way less pressure.
Case shape and volume can alter a powders perceived/exampled burning rate but using the 280A! case for example, I found 7977 to be a little faster burning than H1000 and Rel 26 to be a little faster again, delivering the highest velocities using 150gn BT's.
Moving to the .30/06 case and 200 grain bullets, I found the various 200 grain bullets generated different velocities which is not unexpected, as there is variation in design and bearing surface between them. Using the Partition, I found same/similar velocities with both 62 and 63 grains topping out both the velocity and case volume but it's an honest 2700fps load with a 22" barrel in my Model 70 Featherweight,
