I have been wanting to build a 338 on either the new short mag case or the 30-06 case,any info or help would be greatly appreciated. Brian

I love my .338-06 but I am secretly lusting for a M70fthwt. in .338WSM. I think you could get a bit more perf. out of the short fat case & a couple of guys here have been shooting wildcat .338/.300WSM.

I much prefer the 338-06. Holds more rounds in the mag, and I can't see where the extra velocity of the Magnum would help in the real world. I used to hunt with a 338 Win Mag. but I gave up on it after I started playing with the 338-06, (not that there was anything wrong with it, it just didn't impress me enough to keep it, judgeing on my experience)
Every animal I have ever hunted that might require more power than is available in the 338-06 is an animal that I would want a bigger diameter and heavier bullet for, not just the same bullet faster.

I love the 338 bore for about everything in N. America, but if I were to shoot something more powerful than my 338-06, I'd grab my 375 H&H, 416 Taylor, or 404 Jeffery or 458.
In N. America you don't usually hunt things bigger than moose, and the 338-06 is fine for them. If I were going hunting for Bison or Alaskan Brown bears, the slight difference in power between the 06 and the Mag cases is not going to really be that much. If You need "bigger" than a 338-06 I'd say go LOTS bigger.

I agree. The difference won't be all that great, but either way you won't go wrong.
The 338 WSM is fairly novel, and three down is all you need anyway. Then again, the 338-06 has that "sleeper" appeal known mostly to those using it, hidden to gun wroters for the most part.
If you have a standard (long) action, I'd give consideration to some of the improved '06 cases, like I think Howell's, or the Hawk, and throat so as to seat your bullets as far as is comfy.
An improved case with the shoulder forward, .30" long neck, would give you around 72, 72g water, compared to 67 for standard 338-06. And a COL of 3.45" (or 3.5" for 250g) or so might surprise you.
Call it the 330-06.
The WinMag does -what?- 2650 fps with a 250g? And the 338-06 will do about 2550.
I'd bet you could split the difference. That would be pretty neat.
And if it's throated right, some of those really long low-drags could fit even longer.
Yes, you're right. I am very adept at spending others' money!

.338-284 win!!!!

"Now you can get LESS performance using MORE expensive brass!!! That's right, folks. Act now, 'cause deals like this won't last forever!!"

[teasing. The .284 W case is another worthy alternative, and certainly wins the prize for not doing anything more than the 338-06!! ]