Well, the creedMOOR has some pretty good engineering on its side, which can't be said for the .30-06. About all it had going for it was that it was better than the .30-40 Krag, which was rimmed. Considering that the Argentine Mauser had been out for over two years, that was flat out pathetic. So the '06 isn't the worst thing we've ever done, but it was inferior to the Mauser cartridges for military use the day it was released, which of course was itself an attempt to clean up the colossal SNAFU that was the '03.
It's easy to get nostalgic about US service cartridges, but the reality is that we were very bad at cartridge design compared to pretty much every else in that era.
I don't know enough about cartridge design to comment on the 6.5 Creedmore, but it does shoot well. No idea how well it functions in terms of feed and extraction. It is my considered opinion the 30-06 should not have been adopted, the US would have been better served if the Ordnance Department adopted the 7.5 X 55 Swiss (in the 1890's instead of the 30-40 Krag!). The Swiss round is just at 308 Win ballistics (and we are talking about an 1880's round), it is shorter (semi auto's/full auto's were not a consideration till you got to WW2) so it could have survived after WW2 showed the 30-06 was too long. It has a nice thick rim, which makes it harder to rip the rim off during extraction. This is
if the Ordnance Department had to have a 30 caliber, I think the actual intelligent decision for 1903 would have been to adopt the 6.5 X 55 cartridge in a M1898 actioned rifle.
The only good cartridge cartridge the Ordnance Bureau came up with was the 276 Pedersen, but the types who hate change came up with bogus reasons to stick with the 30-06. The 276 Pedersen would have made an excellent intermediate range combat round.
However, as a hunting round, the 30-06 does just fine.
Comparisons between the 30-06 and 308 have killed lots of electrons. In my experience target shooting, the heaviest bullet a 308 can push with a decent velocity is a 190. The 30-06 was developed with the 220, I only shot up to 200's in the 30-06. The 7.62 Nato was developed to be a 30-06 short, it pushes a 150 grain bullet to the same velocity as the 30-06, it does so with higher pressure, as the case capacity is less. I found the 308 Win to be an excellent target round, and I preferred it to the 30-06 because I rolled around less when manipulating the bolt rapid fire, and it kicked less for the same velocity. The 30-06 probably has an edge in accuracy beyond 600 yards, because you can push the bullet 100 to 150 fps faster, but I can't prove it on target.
With the old military match bullet, which was a decent bullet, but inferior to the SMK's, there is not a whole bunch of difference between 7.62 Match and 30-06 Match out to 600 yards. Maybe if the bullet was better the targets might have shown a difference, but, without an actual comparison, this is only conjecture.
I water marked these to keep Bart B from stealing them, and I made my accounts hidden so he could not again get into my photo accounts and delete images that contradicted his claims that the 30-06 could not shoot straight. I am quite sure he was the one that got into my Photobucket account and deleted this image, for 10 years later he was using one of them. It took me about ten years to go find the paper copy and rescan and rehost the picture.