Were we ever spoiled!
Awhile back on another thread Kraig said something to the effect that for humping around in the boondocks, the lightweight A1 like in RVN or SP1 Colt made sense, and I totally agree. For shooting with irons while cruising around they are very comfortable, especially for physically challenged old timers such as myself. For range duty, a NATO barreled SP2 helps with accuracy. M4s get you back to the A1 weight. It's not easy to get glass to sit on the carry handle of A1 or A2. I like the Sig 556 for that, and it's not light either. I guess none of us appreciated the luxury that was extended us in Nam!