Not my first rodeo; not afraid to cautiously work "off the reservation" in load development. I know how to not blow myself up, so we can withhold the "you'll shoot your eye out kid" replies.
The game plan is to work up a long range (500+ yards) load in .30-06 using NOE's 311299 GC clone. 2400 is on hand in quantity and been rejected for my pistol applications, but it's a good fit for cast in rifles and it's not doing anything else...
The load data for cast in the latest Lyman manual for the .30-06 is a little bit fishy, at best. They bounce between PSI and CUP for pressure with considerable abandon.
Also, they list a max load of 21 grains for my 200 grain bullet at 1736 fps and 27,300 PSI, yet the 10 grains heavier, longer bearing surface 311284 goes to 24 grains, 1827 fps, and 32,000 CUP. They also list the 170 grain 311291 at 43,100CUP with a 29.5 grain charge.
They're running Unique (faster than 2400) and 4759 (a little slower) for 160 grain cast to over 50,000 PSI
So, given that the .30-06 and modern sporting arms are rated for pressures much higher than the good folks at Lyman are listing for 2400, my question is this:
What are the characteristics of 2400 that are causing Lyman to put their max loads where they do? Barring data to the contrary, my inclination is to work steadily upwards over the chronograph until erratic velocities and/or pressure signs tell me to stop.
What says the Hive Mind?