Hello Friends: I have enjoyed this forum for a while and sometimes get some good help here. I have a pre WWII M70 Win. that I finally shot the barrel out of. It was a 30/06AI. It is at the gunsmiths now getting a complete overhaul, stock, trigger adj., barrel etc.. It will come home a 338-06AI. The Ackley stuff is about the kindness to brass it offers not an effort for velocity. I have very little information on powders to try with this caliber. I will be using 210 grain Noslers mostly. If any of you folks can offer some advice I'll sure take it. Take care and shoot straight

IMR 4320 seems to be close to an optimum in the regular .338/'06. It might be a bit fast in the improved; maybe not. But powders in the 4350 range should work, particularly with 250 grain and heavier bullets.

Starting with the cheapest load data you could download the free program "LoadBase" that you will find here. It uses the Powley formulas which are freeware.

Then consider getting a chrongraph and just reading pressure signs. The maximun loads will be specific to your gun anyway.

You could just start with 30/06 data for a starting load if the powder is in the 4320 burning range.

Also buy the book "Wildcat Cartridges" from Wolfe. It has a cartridge in there called the .338 HGT which is a 40 Degree .270 Winchester case for a basis. With the 250 Sierra for a bullet 4350 was filled to the base of the neck and 4831 was compressed from the top of the neck for maximum loads.

Hope this helps.

I find that the standard 30/06 cases last forever but if I was doing a .338 on that case I would improve it also for the capacity.