If it was in .308, it would be a perfect MG--very accurate, etc. Increase mag capacity, maybe even add a drum for fixed mount variants.
HOWEVER--i'm not stupid. It is heavy, wouldn't be fun to lug around, and would be a nightmare for logistical support. HOWEVER--it'd be a perfect fit for the navy, where it's still a ship-borne force that could take oodles of .308, or .30-06, still. Accurate enough single shots, plenty easy to use FA if on a pintle mount. Would come in handy against suicide boats like in the Cole's instance.
Own (among others): S&W 620
RRA 16" Middy AR15
M1 Garand, July '42
M1 Carbine, Inland '43