If the 308 is 50 to 60% more accurate then the 30-06, then the 30 gibbs must be even more inaccurate, the 300WM a horror, the 300WBY an absolute disaster, and the 300RUM an absolute joke.
I love how we use 1960's test data to reflect the options and technology available today. I guess back then there were no sub MOA 06's M1 but lots of better M14's (surprise!!!!).
Except for the WM, I have owned and shot all of the other 30cal cases. ALL can be made to shoot EQUALLY well. Since there are no shortage of LR records held by the 300WM, I guess that case shoots 'ok' too overly short case neck and all.
The only thing that case capacity does is allow for higher velocity potential given the same bullet. It rarely affects accuracy to that extent. Of course, recoil is higher but then performance is rarely a free lunch.
As to smaller targets, ever wonder if bullet, powder, and barrel technology were also getting better about the same time?
Since we are talking service rifles, I don't think the cartridge would be the deciding factor when you are talking about the accuracy of the Garand vs the M14. I would bet that a M14 would outshoot a Garand in 308 on average.
So to the original post, yes, the 30-06 can be a very good 30cal moderate weight bullet launcher. Is it better then the 308? only in max velocity potential. It will recoil more but then the more powder you burn....
Are there better choices? Depends on what you want to use it for.....
Jerry