Requirements for Replacement of Currently Issued 5.56 M-855 and 7.62 M-80.

[stanc]

The Garand was only one weapon in the mix of Thompsons, BAR's, M1 Carbines, and Browning M1919 machineguns...

That's true, but the Garand was the one standard weapon for the majority of US riflemen. Thompsons were used in fewer numbers, and not by most members of an infantry squad/platoon. The BAR was the squad auto of its day. Your statement not only makes it sound as if the Garand saw only limited use, it ignores my point: that one caliber can be -- and has been -- successfully used for the standard-issue rifle and machine gun.

England had a much more viable cartridge at the time in many respected military professionals' opinion, and that was of course the .280 Enfield.

Which, ironically, was intended for a one-caliber system...

Does this shed a little more light on why a single-caliber system doesn't make sense?

Hey, I'm inclined to agree that -- all things considered -- a two-caliber system is better than a unified caliber. All I'm saying is that a one-caliber system can work well...providing the right cartridge is chosen, that is. Plus, for those concerned with fighting a future enemy equipped with hard body armor, 5.56x45 may be inadequate, and require a much more capable caliber.