The M14 is 44 inches long and weighs just over 8 1/2 pounds- not exactly like carrying a BAR around. There is (or should be) some requirement for strength and endurance for soldiers. After all, the WWII infantryman carried a much heavier rifle, and we won that one...Well, we were much tougher a populace in WWII.... you ever seen the pasty mounds of leavened dough that walk our streets these days? :o)
If you couple the weapon's weight with the quite-heavy ammo, and you have a gen-yoo-ine burden. However, yes, the BAR was like lugging a small bank vault around.
"you ever seen the pasty mounds of leavened dough that walk our streets these days?"
Hey! Let's not insult bread...it's not as fat!