Being big and strong sure makes a difference in hauling it and its ammo around. I think they gave it to me since I was 6.2"...
I think a lot of firefights in Afghanistan ended up being at long ranges, so the Marines went for relatively more 7.62 firepower with platoon MGs and squad designated marksmen with 7.62 rifles. Hopefully someone will correct me if that’s incorrect, but I don’t think it is.