I agree about the stock dies and being able to buy ammo most anyplace.
Just seems to me as if a third more powder for 300 fps is not a good trade off. A 300 Win Mag in a 15 inch barrel has to be a handful and if you have a muzzel break it must move cement blocks at the firing line.
With your long case you are trying to burn 70 grains of a slow powder in 12.3 inches of barrel. That's 0.869 cubic inches of barrel and .441 cubic inches of powder, 50%, can't be done.
I have 30 Alaskan dies, so making a 308AI X 444 does not involve new custom dies.
JD Jones claims great things for his 30-06 JDJ, case capacity for my proposal is about the same.
Bottom line: I am looking for information from someone who has loaded 309JDJ in an Encore at Encore pressure. What part of ENCORE don't you understand. :?