As someone with a strong thermodynamics / heat transfer / fluid mechanics background, I agree wholeheartedly with your reasoning and comments here.
Agreed, though it should be noted that results with the .30 M1 carbine in the Pacific by Marines and Navy personnel was generally favorable, and was found at least as suitable for such purposes by those of the British Eighth Army's *Desert Rats* recon units who could scrounge a carbine, considered preferable to any 9mm or .45 machinepistol available from the inventory of either side. Likewise the Brits in postwar Malaya and Kenya found the carbine and it's ammo quite okay, as did the French in Indo-China, followed by many US advisors, ROKs and Vietnamese and other US troops there, including Air America flight crews and spooks who could carry anything they liked.
On the other hand, the American paratroopers at the Battle of the Bulge found that the carbine was ineffectual, as did the Marines at the Chosin Reservoir and Pork Chop Hill determined. The effect may be related to heavy winter clothing, the effect of cold weather on the human vascular system or both and other factors, but shouldn't be dismissed- and should be considered carefully in light of similar observations about the M4 carbine's effectiveness in a warm place.
My own backround is more in the internal ballistics field rather than thermodynamics / heat transfer / fluid mechanics or terminal ballistic effect, but it still gives me enough of an interest to observe such factors and resulting arguments with both a sceptical eye and continuing curiousity. And an occasional opportunity to put the resulting theories into practice.