Soldier of Fortune magazine did a comparison test of full-auto fire from .308 battle rifles, vs. an old BAR. FAL, G-3, something else...
Anyway, firing at a bushel-basket sized boulder at some 500 meters, the BAR was the only one which was held on target for more than two or three shots. The BAR, with its heavier weight, was much easier to control. (The BAR is truly a fun way to turn money into noise, by the way.)
The M-2 Carbine and the M-16 are easy to control on full-auto. I've not fired an AK-47, but judging by the weight I'd assume it's readily controlled.
Watching some Mexican Army soldiers with FALs, I was struck by the thought that somebody 5'-5", 120 pounds, might have a bit of difficulty with full auto...
The original intent of the .270 was to have a hunting rifle suitable for elk and smaller game, but with a bit less recoil than the '06. With development of such cartridges as the 7mm-08, etc., and the advances in bullet technology, its desireability is lessened. It still "works" quite well, of course, but it does not have the advantage it once had, over cartridges such as the 7X57 or the .257 Roberts.
FWIW, Art