Huh, what war-crazed urge would tempt someone to carry a 120lb Browning M2 around, I wonder...
I'd rather go in favor of carrying a lighter rifle with lots of ammuntion. Like say I was serving in WWII. I'd probably pick the M1 Carbine over the M1 Garand, because it is lighter and holds more bullets. While most men only carried 4 or 5 magazines in total, I'd stuff as many to my belt as possible. And only two 7 round magazines for the .45? No way.
The fact the FN FAL Carbine and the ammunition it fires are very heavy, from a tactical value that doesn't impress me much. Sure the heavy weight reduces the recoil, and the 7.62 rounds can punch some good holes, but if you can't haul ass under fire because your being weighed down by tons of metal, it won't matter what weapon you carry, you'll just make a good corpse.