All I can add to this conversation is as follows..... and forgive me if it is of no interest to your question...
I have a 338/06 which was a rebore on a 270 barrel on a Model 70 LA.
A good friend has a 338/06 AI on a Ruger Long Action, and an ER Shaw chambered barrel...
We were together at the range one day with our chronographs... just ran into each other testing loads and happen to have the 338/06s with us..
We had several loads using the same powder and bullets... both with 24 inch barreled rifles..
Mine consistently had about 100 fps more velocity than his did using the same bullets and same powder... although his happened to have a few more grains loaded, it being an AI...
we both were shooting 200 and 225 grain Hornady SPs in ours...
the best accuracy was using H 380 powder for both of us...and also pretty close to top in velocity also...
Greg replaced his barrel ( and sold it) and rebarreled with a Shaw 338/06 barrel.... that one did better in velocity than the AI version
and was less fincky, being able to skip the fireforming step on the brass...
best of luck on your choice...338/06 is a damn fine caliber... my 338 mag has been a dust collector ever since...
I'd get rid of the 338 Mag, if I didn't have the flaw of not getting rid of an accurate rifle... the 338 Mag is also a Model 70...
I have a 338-06. I neck up '06 brass, easy using sizer with tapered expander. All my 338-06 ammo has '06 headstamps...
Don't think I'd go AI with that one. Seems to me the reward wouldn't justify the hassle..
DF
That is pretty much all I do... I got a tapered expander for free from RCBS...
I have ran across a few guys, who use 280 and 280 AI brass instead, and they get a little more velocity...
but what they are really shooting is a 338/280 instead of a 338/06, even tho that is what they call it and what the barrel was stamped..
