Where do you see that IMR 3031 has high pressure?look at https://www.hodgdonreloading.com/data/rifle I've always stayed away from fast from fast for the caliber powders like 3031. You can see the the pressure is really high compared to say a modern powder like CFE 223 to get the same FPS. The copper foul reducer powders really do work!
I would rather burn more powder at a lower pressure to get the same velocity.
I don't know what to say to you...... if 3031 takes a pressure spike of near the upper limit of psi to get the same fps of a modern slower powder with 9K less pressure. What don't you understand about the hodgdon reloading link I posted?Where do you see that IMR 3031 has high pressure?
Your link doesn't even show any .308 Win IMR 3031 loads.
|Min Powder Charge||Maximum Powder Charge|
|Hodgdon Manual||41.5gr 2518 FPS 43,800 PSI||43.9gr 2653 FPS 52,000 PSI|
|Hornady Manual||36.1gr 2100 FPS||41.6gr 2500 FPS|