3.340 inch is the usual listed max COL for the 30-06.
Most US made factory ammo is pretty short these days.
I just checked my hand-load log-book and quite a few of my heavier bullet loads in the 30-06 are at 3.300 col.
My 338-06 pretty much only likes 225 grain bullets for some reason. My loads for that fall between 3.250 and 3.350 inches COL depending on the bullet type / brand.
As mentioned by Brother 35 Whelen, who might get away with it by short loading. Or whack off some barrel from the threaded end and have it re-threaded and reamed to 338 Federal. (338-308)
OR.... Have the bolt face and mag rails opened up and chamber it for the 338 Ruger Compact Mag. That cartridge is a real barn burner. (and shoulder whacker)
Of course the original 8mm Mauser will do anything that a 338 federal can do...
The 35 Whelen is a nice cartridge.
While some folks like to blow the horn of better BC and sectional density of the 338, a side by side caparison of similar bullet types and weights will show that out to 300 yards the 338-06 and 35 Whelen are usually within one inch of each other on the trajectory chart.
Hunting big game past 300 yards is somewhat un-sportsman like, thus within that range, the 338-06 and 35 Whelen are virtually tied.