That was my point in reference to the "under powered" comments from earlier.
The 7.62mm NATO wasn't the load I was mentioning, that was the U.S. T65 type "improvment" to the 30-06. I was thinking of the "intermediate power" rounds like the .270/280 that were originally in development for the EM-1 & EM-2 series as being comparable with the Soviet 7.62X39 round for the SKS/AK 47 & other similar loads. Those are ballistically similar to the 30-30.
Several countries had experimented with intermediate cartridges before WW2. The Garand was originally intended to be chambered for the .276 Pederson cartridge which was practically identical in performance to the later British .280 in performance.
The British had tested a toggle link autoloader in that .276 caliber before the war.
The modern 6.8 Remington is in that same class.
The British used the No.5 carbine platform in testing of a number of intermediate cartridges, including the .280 and 7.62X39. I think these test rifles were single loaders, but some may have been modified to feed from a magazine.
A few have altered Lee Enfields for the 7.62X39 and the 5.56 cartridges in recent years.
The 7.62X39 is near identical to the .30-30 when the later is loaded with 125 gr bullets, but you seldom see the 125 gr .30-30 rounds these days, 150-170 gr being the standard loads.
The Remington autoloaders in .30 Remington (basically a rimless .30-30) , and fitted with long curved box magazines, were used on a small scale in much the same manner as an assault rifle, though without selective fire capability.
I'd have to say that the main battle cartridges were a better choice for most of the fighting done during WW2 and Korea.